submission_id
stringlengths 5
9
| problem_id
stringlengths 3
6
| date
int64 -1
-1
| language
stringclasses 11
values | verdict
stringclasses 1
value | cpu_time
int64 -1
15k
| memory
int64 -1
1.07B
| code
stringlengths 16
11k
| source
stringclasses 1
value | testcount
int64 0
604
| lenght
int64 16
11k
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|---|---|---|---|---|---|---|---|---|---|---|
s681968706 | p04051 | 1,569,214,767 | cpp | Accepted | 206 | 64,640 | // 23;23
#include <algorithm>
#include <iostream>
#include <cstdio>
#define rint register int
#define N 200005
#define M 2003
using namespace std;
const int Mod = 1e9 + 7;
const int eps = 2001;
int n, a[N], b[N], f[M << 1][M << 1];
int fac[M << 2], inv[M << 2], ifac[M << 2];
inline void prework() {
fac[0] = inv[1] = ifac[0] = 1;
for (rint i = 1; i <= eps << 2; ++i)
fac[i] = 1ll * fac[i - 1] * i % Mod;
for (rint i = 2; i <= eps << 2; ++i)
inv[i] = 1ll * inv[Mod % i] * (Mod - Mod / i) % Mod;
for (rint i = 1; i <= eps << 2; ++i)
ifac[i] = 1ll * ifac[i - 1] * inv[i] % Mod;
}
inline int C(int x, int y) {
return 1ll * fac[x + y] * ifac[x] % Mod * ifac[y] % Mod;
}
int main() {
#ifdef whyqx
freopen("work.in", "r", stdin);
freopen("work.out", "w", stdout);
#endif
prework(); cin >> n;
for (rint i = 1; i <= n; ++i)
scanf("%d%d", a + i, b + i),
++f[eps - a[i]][eps - b[i]];
for (rint i = 1; i <= eps << 1; ++i)
for (rint j = 1; j <= eps << 1; ++j)
(f[i][j] += (f[i - 1][j] + f[i][j - 1]) % Mod) %= Mod;
long long ans = 0;
for (rint i = 1; i <= n; ++i)
(ans += f[eps + a[i]][eps + b[i]]) %= Mod;
for (rint i = 1; i <= n; ++i)
(ans -= C(a[i] << 1, b[i] << 1)) %= Mod;
cout << 1ll * (ans % Mod + Mod) % Mod * ((Mod + 1) >> 1) % Mod;
return 0;
}
| codenet | -1 | 1,382 |
s681968706 | p04051 | 1,569,214,767 | cpp | Accepted | 206 | 64,640 | // 23;23
#include <algorithm>
#include <iostream>
#include <cstdio>
#define rint register int
#define N 200005
#define M 2003
using namespace std;
const int Mod = 1e9 + 7;
const int eps = 2001;
int n, a[N], b[N], f[M << 1][M << 1];
int fac[M << 2], inv[M << 2], ifac[M << 2];
inline void prework() {
fac[0] = inv[1] = ifac[0] = 1;
for (rint i = 1; i <= eps << 2; ++i)
fac[i] = 1ll * fac[i - 1] * i % Mod;
for (rint i = 2; i <= eps << 2; ++i)
inv[i] = 1ll * inv[Mod % i] * (Mod - Mod / i) % Mod;
for (rint i = 1; i <= eps << 2; ++i)
ifac[i] = 1ll * ifac[i - 1] * inv[i] % Mod;
}
inline int C(int x, int y) {
return 1ll * fac[x + y] * ifac[x] % Mod * ifac[y] % Mod;
}
int main() {
#ifdef whyqx
freopen("work.in", "r", stdin);
freopen("work.out", "w", stdout);
#endif
prework(); cin >> n;
for (rint i = 1; i <= n; ++i)
scanf("%d%d", a + i, b + i),
++f[eps - a[i]][eps - b[i]];
for (rint i = 1; i <= eps << 1; ++i)
for (rint j = 1; j <= eps << 1; ++j)
(f[i][j] += (f[i - 1][j] + f[i][j - 1]) % Mod) %= Mod;
long long ans = 0;
for (rint i = 1; i <= n; ++i)
(ans += f[eps + a[i]][eps + b[i]]) %= Mod;
for (rint i = 1; i <= n; ++i)
(ans -= C(a[i] << 1, b[i] << 1)) %= Mod;
cout << 1ll * (ans % Mod + Mod) % Mod * ((Mod + 1) >> 1) % Mod;
return 0;
}
| codenet | -1 | 1,382 |
s181439014 | p04051 | 1,473,242,925 | cpp | Accepted | 987 | 172,800 | #include <iostream>
using namespace std;
const int KMAX = 200000 + 5;
const int N = 2000 + 5;
const int MOD = 1000000000 + 7;
const int INV2 = 500000000 + 4;
int comb[4 * N][2 * N];
void precalc_comb() {
for (int i = 0; i < 4 * N; ++ i) {
comb[i][0] = 1;
for (int j = 1; j <= i && j < 2 * N; ++ j) {
comb[i][j] = comb[i - 1][j - 1] + comb[i - 1][j];
if (comb[i][j] >= MOD)
comb[i][j] -= MOD;
}
}
}
int K;
int A[KMAX];
int B[KMAX];
int dp[2 * N][2 * N];
int main()
{
ios_base :: sync_with_stdio(false);
cin >> K;
for (int i = 1; i <= K; ++ i)
cin >> A[i] >> B[i];
for (int i = 1; i <= K; ++ i)
++ dp[N - A[i]][N - B[i]];
for (int i = 1; i < 2 * N; ++ i)
for (int j = 1; j < 2 * N; ++ j) {
dp[i][j] += dp[i][j - 1];
if (dp[i][j] >= MOD)
dp[i][j] -= MOD;
dp[i][j] += dp[i - 1][j];
if (dp[i][j] >= MOD)
dp[i][j] -= MOD;
}
precalc_comb();
int ans = 0;
for (int i = 1; i <= K; ++ i) {
ans += dp[N + A[i]][N + B[i]];
if (ans >= MOD)
ans -= MOD;
ans -= comb[A[i] + B[i] + A[i] + B[i]][A[i] + A[i]];
if (ans < 0)
ans += MOD;
}
ans = (1LL * ans * INV2) % MOD;
cout << ans << '\n';
return 0;
}
| codenet | -1 | 1,385 |
s346264439 | p04051 | 1,501,812,665 | cpp | Accepted | 174 | 126,976 | //such a genius problem!
#include <bits/stdc++.h>
#define FI(i,a,b) for(int i=(a);i<=(b);i++)
#define FD(i,a,b) for(int i=(a);i>=(b);i--)
#define LL long long
#define Ldouble long double
#define PI 3.14159265358979323846264338327950288419
#define PII pair<int,int>
#define PLL pair<LL,LL>
#define mp make_pair
#define fi first
#define se second
using namespace std;
#define mod 1000000007
#define C 2001
int n, a[200005], b[200005];
int grid[4005][4005], dp[4005][4005], ans;
int po(int A, int B){
int c = 1, d = A;
while(B){
if(B & 1) c = 1LL * c * d % mod;
d = 1LL * d * d % mod;
B >>= 1;
}
return c;
}
int fact[8004], inv[8004];
int ncr(int N, int R){
return (1LL * fact[N] * inv[R]) % mod * inv[N - R] % mod;
}
int main(){
fact[0] = inv[0] = 1;
FI(i, 1, 8000){
fact[i] = 1LL * fact[i - 1] * i % mod;
inv[i] = po(fact[i], mod - 2);
}
scanf("%d", &n);
FI(i, 1, n){
scanf("%d %d", &a[i], &b[i]);
grid[C - a[i]][C - b[i]]--;
grid[C + a[i]][C + b[i]]++;
}
FI(i, 1, 4002) FI(j, 1, 4002){
dp[i][j] = (dp[i - 1][j] + dp[i][j - 1]) % mod;
if(grid[i][j] < 0){
dp[i][j] = (dp[i][j] - grid[i][j]) % mod;
}
if(grid[i][j] > 0){
ans = (ans + 1LL * grid[i][j] * dp[i][j]) % mod;
}
}
FI(i, 1, n) ans = (ans - ncr(2 * (a[i] + b[i]), 2 * b[i])) % mod;
ans = 1LL * ans * po(2, mod - 2) % mod;
printf("%d\n", (ans + mod) % mod);
return 0;
}
| codenet | -1 | 1,386 |
s917345681 | p04051 | 1,590,089,111 | cpp | Accepted | 107 | 64,512 | #include<bits/stdc++.h>
using namespace std;
#define REP(i,a,b) for(int i=(a),_ed=(b);i<=_ed;++i)
#define DREP(i,a,b) for(int i=(a),_ed=(b);i>=_ed;--i)
#define mp(x,y) make_pair((x),(y))
#define sz(x) (int)(x).size()
#define pb push_back
typedef long long ll;
typedef pair<int,int> pii;
inline int read(){
register int x=0,f=1;register char ch=getchar();
while(!isdigit(ch)){if(ch=='-')f=0;ch=getchar();}
while(isdigit(ch)){x=x*10+(ch^'0');ch=getchar();}
return f?x:-x;
}
const int mod=1000000007;
int n,a[200005],b[200005],f[4005][4005],fac[8005],ifc[8005];
#define f(x,y) f[x+2000][y+2000]
inline void inc(int& x,int y){x=x+y<mod?x+y:x+y-mod;}
inline void dec(int& x,int y){x=x-y>=0?x-y:x-y+mod;}
inline int power(int b,int n){int ans=1;for(;n;n>>=1,b=1ll*b*b%mod)if(n&1)ans=1ll*ans*b%mod;return ans;}
inline int C(int n,int m){return (n<0||m<0||n<m)?0:1ll*fac[n]*ifc[m]%mod*ifc[n-m]%mod;}
int main(){
// freopen("in.in","r",stdin);
REP(i,fac[0]=1,8001)fac[i]=1ll*fac[i-1]*i%mod;
ifc[8001]=power(fac[8001],mod-2);
DREP(i,8001,1)ifc[i-1]=1ll*ifc[i]*i%mod;
n=read();
REP(i,1,n){
a[i]=read(),b[i]=read();
++f(-a[i],-b[i]);
}
REP(i,-2000,2000)REP(j,-2000,2000)
inc(f(i+1,j),f(i,j)),inc(f(i,j+1),f(i,j));
int ans=0;
REP(i,1,n)inc(ans,f(a[i],b[i]));
REP(i,1,n)dec(ans,C(a[i]*2+b[i]*2,a[i]*2));
ans=1ll*ans*(mod+1)/2%mod;
printf("%d\n",ans);
return 0;
}
| codenet | -1 | 1,387 |
s129621965 | p04051 | 1,541,014,873 | cpp | Accepted | 127 | 64,512 | #pragma GCC optimize(2)
#pragma GCC optimize(3)
#pragma GCC optimize("Ofast")
#include<iostream>
#include<cstdio>
#include<cstring>
#define ll long long
#define p 1000000007
using namespace std;
inline int get(){
int n=0;char c;while((c=getchar())||23333){
if(c>='0'&&c<='9')break;if(c=='-')goto s;
}n=c-'0';while((c=getchar())||23333){
if(c>='0'&&c<='9')n=n*10+c-'0';else return(n);
}s:while((c=getchar())||23333){
if(c>='0'&&c<='9')n=n*10-c+'0';else return(n);
}
}
int dp[4001][4001];ll jc[8001],jcny[8001];
inline ll mi(int a,int b){
ll ans=1,tmp=a;while(b){
if(b&1)ans=(ans*tmp)%p;tmp=(tmp*tmp)%p;b>>=1;
}return(ans);
}int xs[200001],ys[200001];
inline ll cnm(int n,int m){
ll cjr=jc[n]*jcny[m];cjr%=p;cjr*=jcny[n-m];cjr%=p;return(cjr);
}
int main(){
int n=get();for(register int i=1;i<=n;i++){
xs[i]=get();ys[i]=get();dp[2000-xs[i]][2000-ys[i]]++;
}jc[0]=1;for(register int i=1;i<=8000;i++)jc[i]=(jc[i-1]*i)%p;
jcny[8000]=mi(jc[8000],p-2);for(register int i=7999;i>=0;i--)jcny[i]=(jcny[i+1]*(i+1))%p;
for(register int i=0;i<=4000;i++){
for(register int j=0;j<=4000;j++){
if(i-1>=0)dp[i][j]+=dp[i-1][j];
if(j-1>=0)dp[i][j]+=dp[i][j-1];dp[i][j]%=p;
}
}ll ans=0;for(register int i=1;i<=n;i++){
ans+=dp[2000+xs[i]][2000+ys[i]];
ans-=cnm(xs[i]+xs[i]+ys[i]+ys[i],xs[i]+xs[i]);ans%=p;ans+=p;ans%=p;
}ans*=mi(2,p-2);ans%=p;cout<<ans<<endl;
return(0);
} | codenet | -1 | 1,387 |
s282504647 | p04051 | 1,493,200,483 | cpp | Accepted | 230 | 65,792 | #include <bits/stdc++.h>
using namespace std;
const int EXP = 2e3 + 3;
const int DIM = 4e3 + 5;
const int MOD = 1e9 + 7;
pair<int, int> arr[DIM * DIM];
int fct[DIM * 2], inv[DIM * 2], dp[DIM][DIM];
inline int lgput( int x, int n ) {
if( n == 0 )
return 1;
int y = lgput( x, n / 2 );
y = ( 1LL * y * y ) % MOD;
if( n % 2 == 1 )
y = ( 1LL * y * x ) % MOD;
return y;
}
inline int comb( int n, int k ) {
return ( ( ( 1LL * fct[n] * inv[k] ) % MOD ) * inv[n - k] ) % MOD;
}
int main( void ) {
fct[0] = inv[0] = 1;
for( int i = 1; i < DIM * 2; i ++ ) {
fct[i] = ( 1LL * fct[i - 1] * i ) % MOD;
inv[i] = lgput( fct[i], MOD - 2 );
}
int n;
cin >> n;
for( int i = 1; i <= n; i ++ ) {
cin >> arr[i].first >> arr[i].second;
dp[EXP - arr[i].first][EXP - arr[i].second] ++;
}
for( int i = 1; i < DIM; i ++ )
for( int j = 1; j < DIM; j ++ )
dp[i][j] = ( dp[i][j] + dp[i - 1][j] + dp[i][j - 1] ) % MOD;
int ans = 0;
for( int i = 1; i <= n; i ++ ) {
ans = ( ans + dp[EXP + arr[i].first][EXP + arr[i].second] ) % MOD;
ans = ( ans - comb( ( arr[i].first + arr[i].second ) * 2, arr[i].first * 2 ) + MOD ) % MOD;
}
ans = ( 1LL * ans * lgput( 2, MOD - 2 ) ) % MOD;
cout << ans << endl;
return 0;
} | codenet | -1 | 1,387 |
s918685324 | p04051 | 1,537,199,240 | cpp | Accepted | 122 | 67,712 | #include<iostream>
#include<cstring>
#include<cstdio>
#include<algorithm>
#define gc getchar()
#define lint long long
#define mod 1000000007
#define debug(x) cerr<<#x<<"="<<x
#define sp <<" "
#define ln <<endl
#define f(x,y) dp[(x)+BAS+5][(y)+BAS+5]
#define N 200010
#define BAS 2010
#define rep(i,a,b) for(int i=a;i<=b;i++)
using namespace std;
inline int inn() { int x,ch;while((ch=gc)<'0'||ch>'9');x=ch^'0';while((ch=gc)>='0'&&ch<='9')x=(x<<1)+(x<<3)+(ch^'0');return x; }
int a[N],b[N],dp[BAS*2+100][BAS*2+100],fac[N],facinv[N];
inline int fast_pow(int x,int k,int ans=1) { for(;k;k>>=1,x=(lint)x*x%mod) (k&1)?ans=(lint)ans*x%mod:0;return ans; }
inline int S(int n)
{
rep(i,1,n) f(-a[i],-b[i])++;int ans=0;
rep(i,-BAS,BAS) rep(j,-BAS,BAS) if(f(i,j)) f(i+1,j)+=f(i,j),f(i,j+1)+=f(i,j),(f(i+1,j)>=mod?f(i+1,j)-=mod:0),(f(i,j+1)>=mod?f(i,j+1)-=mod:0);
rep(i,1,n) ans+=f(a[i],b[i]),(ans>=mod?ans-=mod:0);return ans;
}
inline int prelude(int n)
{
rep(i,fac[0]=1,n) fac[i]=(lint)fac[i-1]*i%mod;facinv[n]=fast_pow(fac[n],mod-2);
for(int i=n-1;i>=0;i--) facinv[i]=(i+1ll)*facinv[i+1]%mod;return 0;
}
inline int C(int n,int m) { return (lint)fac[n]*facinv[n-m]%mod*facinv[m]%mod; }
int main()
{
int n=inn();rep(i,1,n) a[i]=inn(),b[i]=inn();int ans=S(n);prelude(10000);
rep(i,1,n) ans-=C(2*a[i]+2*b[i],2*a[i]),(ans<0?ans+=mod:0);
return !printf("%lld\n",(lint)fast_pow(2,mod-2)*ans%mod);
} | codenet | -1 | 1,390 |
s959588547 | p04051 | 1,538,193,147 | cpp | Accepted | 180 | 101,376 | #include <bits/stdc++.h>
using namespace std;
const int N = 200005;
const int offset = 2005;
const int mod = 1000000007;
void add(int &x,int y) {
x += y; if (x >= mod) x -= mod;
}
int mul(int x,int y) {
return (long long) x * y % mod;
}
int pw(int x,int y) {
int ret = 1;
while (y) {
if (y & 1) ret = mul(ret, x);
x = mul(x, x);
y >>= 1;
}
return ret;
}
int n;
int a[N], b[N];
vector<int> _get[offset + offset];
int f[offset + offset][offset + offset], upd[offset + offset][offset + offset];
int fac[N], ifac[N];
int calc(int x,int y) {
return mul(fac[x + y], mul(ifac[x], ifac[y]));
}
int main() {
ios_base::sync_with_stdio(false);
cin >> n;
for (int i = 1; i <= n; ++i) {
cin >> a[i] >> b[i];
upd[-a[i] + offset][-b[i] + offset]++;
_get[a[i] + offset].push_back(b[i] + offset);
}
int res = 0;
for (int x = 0; x < offset + offset; ++x) {
for (int y = 0; y < offset + offset; ++y) {
add(f[x][y], upd[x][y]);
if (x > 0) add(f[x][y], f[x - 1][y]);
if (y > 0) add(f[x][y], f[x][y - 1]);
}
for (int y : _get[x]) add(res, f[x][y]);
}
fac[0] = 1;
for (int i = 1; i < N; ++i) fac[i] = mul(fac[i - 1], i);
ifac[N - 1] = pw(fac[N - 1], mod - 2);
for (int i = N - 2; i >= 0; --i) ifac[i] = mul(ifac[i + 1], i + 1);
for (int i = 1; i <= n; ++i) add(res, mod - calc(a[i] + a[i], b[i] + b[i]));
res = mul(res, pw(2, mod - 2));
cout << res << '\n';
}
| codenet | -1 | 1,393 |
s641303225 | p04051 | 1,486,533,826 | cpp | Accepted | 230 | 64,512 | #include<bits/stdc++.h>
using namespace std;
int ans, N, M, mod = 1e9 + 7, a[200009], b[200009], fac[8009], inv[8009], dp[4009][4009];
int add (int x, int y) {int ans = x + y; if (ans >= mod) ans -= mod; return ans;}
int substract (int x, int y) {if (x >= y) return x - y; return x - y + mod;}
int mul (int x, int y) {return 1LL * x * y % mod;}
int pow (int a, int b)
{
int p = 1;
for (int i=0; (1<<i) <= b; i++)
{
if (b & (1 << i)) p = mul (p, a);
a = mul (a, a);
}
return p;
}
void Prec (int lim){fac[0] = inv[0] = 1;for (int i=1; i<=lim; i++)fac[i] = mul (fac[i - 1], i);
inv[lim] = pow (fac[lim], mod - 2);for (int i=lim - 1; i>=1; i--)inv[i] = mul (inv[i + 1], i + 1);}
int comb (int N, int K){int ans = mul (fac[N], inv[N - K]);ans = mul (ans, inv[K]);return ans;}
int main ()
{
//freopen ("input", "r", stdin);
//freopen ("output", "w", stdout);
scanf ("%d", &N), Prec (8000), M = 2000, ans = 0;
for (int i=1; i<=N; i++)
{
scanf ("%d %d", &a[i], &b[i]), dp[M + 1 - a[i]][M + 1 - b[i]] ++;
ans = substract (ans, comb (2 * a[i] + 2 * b[i], 2 * a[i]));
}
for (int i=1; i<=2 * M + 1; i++)
for (int j=1; j<=2 * M + 1; j++)
dp[i][j] = add (dp[i][j], add (dp[i - 1][j], dp[i][j - 1]));
for (int i=1; i<=N; i++)
ans = add (ans, dp[M + 1 + a[i]][M + 1 + b[i]]);
ans = mul (ans, pow (2, mod - 2));
printf ("%d\n", ans);
return 0;
}
| codenet | -1 | 1,396 |
s062170479 | p04051 | 1,578,599,859 | cpp | Accepted | 202 | 101,504 | //IOI 2021
#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define ff first
#define ss second
typedef pair<int, int> pii;
const int MAXN = 200 * 1000 + 1, MAXS = 2 * 1000 + 17, mod = 1e9 + 7;
int sum(int a, int b) {
a += b;
if (a >= mod) a -= mod;
else if (a < 0) a += mod;
return a;
}
int mul(int a, int b) {
return (1LL * a * b) % mod;
}
int pw(int a, int b) {
int res = 1;
while (b) {
if (b & 1)
res = mul(a, res);
a = mul(a, a);
b >>= 1;
}
return res;
}
int n, dp[MAXS << 1][MAXS << 1], x[MAXN], y[MAXN], p[MAXS << 1][MAXS << 1], ans, fac[MAXN], ifac[MAXN];
vector<pii> all;
void prep() {
fac[0] = 1;
for (int i = 1; i < MAXN; i++)
fac[i] = mul(fac[i - 1], i);
for (int i = 1; i < MAXN; i++)
ifac[i] = pw(fac[i], mod - 2);
}
int C(int a, int b) {
return mul(fac[a], mul(ifac[b], ifac[a - b]));
}
int main() {
ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);
prep();
cin >> n;
for (int i = 1; i <= n; i++)
cin >> x[i] >> y[i], p[MAXS - x[i]][MAXS - y[i]]++;
for (int i = 1; i < MAXS << 1; i++)
for (int j = 1; j < MAXS << 1; j++)
dp[i][j] = sum(sum(dp[i - 1][j], dp[i][j - 1]), p[i][j]);
for (int i = 1; i <= n; i++)
ans = sum(ans, dp[x[i] + MAXS][y[i] + MAXS]);
for (int i = 1; i <= n; i++)
ans = sum(ans, -C(2 * x[i] + 2 * y[i], 2 * x[i]));
ans = mul(ans, pw(2, mod - 2));
cout << ans << endl;
return 0;
}
| codenet | -1 | 1,397 |
s344691045 | p04051 | 1,509,057,302 | cpp | Accepted | 197 | 95,360 | #include <bits/stdc++.h>
#define SZ(x) ((int(x.size())))
typedef long long ll;
typedef long double ld;
using namespace std;
const int mod = 1000000007, maxn = 4*1000+10, O = 2005;
ll ans, kam, fac[2 * maxn], caf[2 * maxn];
int n, a, b, dp[maxn][maxn], mark[maxn][maxn];
ll power (ll a, ll b, int m)
{
if (b == 0)
return 1;
ll kmk = power (a, b / 2, m);
if (b & 1)
return (((kmk * kmk) % m) * a) % m;
return (kmk * kmk) % m;
}
void make_fac ()
{
fac[0] = 1;
for (int i = 1; i < 2 * maxn; i++)
fac[i] = (fac[i - 1] * i) % mod;
}
void make_caf ()
{
for (int i = 0; i < 2 * maxn; i++)
caf[i] = power (fac[i], mod - 2, mod);
}
ll C (int R, int N)
{
return (((fac[N] * caf[R]) % mod) * caf[N - R]) % mod;
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
make_fac ();
make_caf ();
cin >> n;
for (int i = 0; i < n; i++)
{
cin >> a >> b;
kam = (kam + C (2 * a, 2 * (a + b))) % mod;
dp[O - a][O - b]++;
mark[O + a][O + b]++;
}
for (int i = 1; i < maxn; i++)
{
for (int j = 1; j < maxn; j++)
{
dp[i][j] = (((dp[i][j] + dp[i - 1][j]) % mod) + dp[i][j - 1]) % mod;
ans = (ans + (((ll)dp[i][j] * mark[i][j]) % mod)) % mod;
}
}
cout << (((ans + mod - kam) % mod) * power (2, mod - 2, mod)) % mod;
return 0;
} | codenet | -1 | 1,398 |
s321234320 | p04051 | 1,590,700,625 | cpp | Accepted | 209 | 97,792 | /*input
3
1 1
1 1
2 1
*/
#include <bits/stdc++.h>
using namespace std;
int read() {
int x = 0, c = getchar();
for(; !(c > 47 && c < 58); c = getchar());
for(; (c > 47 && c < 58); c = getchar()) x = x * 10 + c - 48;
return x;
}
const int maxm = 2005;
const int maxn = 200005;
const int mod = 1e9 + 7;
void add(int &a, int b) {
a = (a + b) % mod;
}
pair<int, int> p[maxn];
int n;
int f[maxm << 1][maxm << 1];
int mark[maxm << 1][maxm << 1];
int mul[maxn], inv[maxn];
int C(int k, int n) {
if(k > n) return 0;
return 1ll * mul[n] * inv[n - k] % mod * inv[k] % mod;
}
int main(){
mul[0] = inv[0] = inv[1] = 1;
for(int i = 1; i < maxn; ++ i) mul[i] = 1ll * i * mul[i - 1] % mod;
for(int i = 2; i < maxn; ++ i) inv[i] = -1ll * (mod / i) * inv[mod % i] % mod + mod;
for(int i = 2; i < maxn; ++ i) inv[i] = 1ll * inv[i] * inv[i - 1] % mod;
n = read();
for(int i = 1; i <= n; ++ i) {
int x = read(), y = read();
mark[x + maxm][y + maxm] ++;
p[i] = make_pair(x, y);
}
for(int i = (maxm << 1) - 1; i; -- i)
for(int j = (maxm << 1) - 1; j; -- j) {
add(f[i][j], mark[i][j]);
add(f[i - 1][j], f[i][j]);
add(f[i][j - 1], f[i][j]);
}
int Ans = 0;
for(int i = 1; i <= n; ++ i) {
int x = p[i].first, y = p[i].second;
int cur = (0ll + f[maxm - x][maxm - y] + mod - C(x + x, (x + y) << 1)) % mod;
add(Ans, 1ll * cur * (mod + 1) / 2 % mod);
}
printf("%d\n", Ans);
} | codenet | -1 | 1,399 |
s710756394 | p04051 | 1,595,589,907 | cpp | Accepted | 289 | 93,516 | #include <bits/stdc++.h>
using namespace std;
const int N = 4069;
const int M = 200010;
const int SHIFT = 2005;
const int MOD = 1e9 + 7;
int n, a[M], b[M], dp[N][N], fac[N << 1], inv[N << 1], dest[N][N];
int call (int x, int y) {
if (x == N or y == N) return 0;
if (~dp[x][y]) return dp[x][y];
dp[x][y] = call(x + 1, y) + call(x, y + 1);
if (dp[x][y] >= MOD) dp[x][y] -= MOD;
dp[x][y] += dest[x][y];
if (dp[x][y] >= MOD) dp[x][y] -= MOD;
return dp[x][y];
}
int bigMod (int a, int e) {
if (e == -1) e = MOD - 2;
int ret = 1;
while (e) {
if (e & 1) ret = (long long) ret * a % MOD;
a = (long long) a * a % MOD, e >>= 1;
}
return ret;
}
inline int comb (int x, int y) {
return (long long) inv[x] * inv[y] % MOD * fac[x + y] % MOD;
}
int main() {
fac[0] = 1;
for (int i = 1; i < N << 1; ++i) {
fac[i] = (long long) i * fac[i - 1] % MOD;
inv[i] = bigMod(fac[i], -1);
}
cin >> n;
for (int i = 1; i <= n; ++i) {
scanf("%d %d", a + i, b + i);
++dest[SHIFT + a[i]][SHIFT + b[i]];
}
memset(dp, -1, sizeof dp);
int ans = 0;
for (int i = 1; i <= n; ++i) {
ans += call(SHIFT - a[i], SHIFT - b[i]);
if (ans >= MOD) ans -= MOD;
}
for (int i = 1; i <= n; ++i) {
int cur = comb(a[i] << 1, b[i] << 1);
ans -= cur; if (ans < 0) ans += MOD;
}
if (ans & 1) ans += MOD; ans >>= 1;
cout << ans % MOD << '\n';
return 0;
}
| codenet | -1 | 1,402 |
s016451953 | p04051 | 1,595,287,914 | cpp | Accepted | 201 | 130,592 | #include<bits/stdc++.h>
#define ll long long
using namespace std;
template<typename T>
void read(T &x)
{
x=0;char c=getchar();bool p=0;
for(;c<'0'||c>'9';c=getchar())if(c=='-')p=1;
for(;c>='0'&&c<='9';c=getchar())x=(x<<3)+(x<<1)+(c^48);
if(p)x=-x;
}
const ll MOD=1000000000+7;
ll ksm(ll basic,ll mi)
{
ll tmp=1;
while(mi)
{
if(mi&1)tmp=tmp*basic%MOD;
mi>>=1;
basic=basic*basic%MOD;
}
return tmp;
}
ll f[4005][4005];
int a[200005],b[200005],n;
ll fac[8005],inv[8005];
ll C(ll x,ll y)
{
return fac[x]*inv[y]%MOD*inv[x-y]%MOD;
}
int main()
{
fac[0]=inv[0]=1;
for(ll i=1;i<=8000;++i)fac[i]=fac[i-1]*i%MOD;
inv[8000]=ksm(fac[8000],MOD-2);
for(ll i=7999;i;--i)inv[i]=inv[i+1]*(i+1)%MOD;
read(n);
for(int i=1;i<=n;++i)
{
read(a[i]),read(b[i]);
++f[-a[i]+2000][-b[i]+2000];
}
for(int i=0;i<=4000;++i)
{
for(int j=0;j<=4000;++j)
{
if(i)f[i][j]=(f[i][j]+f[i-1][j])%MOD;
if(j)f[i][j]=(f[i][j]+f[i][j-1])%MOD;
}
}
ll ans=0;
for(int i=1;i<=n;++i)
{
ans=(ans+f[a[i]+2000][b[i]+2000])%MOD;
}
for(int i=1;i<=n;++i)
{
ans=(ans-C(2*a[i]+2*b[i],2*a[i])+MOD)%MOD;
}
ans=ans*ksm(2,MOD-2)%MOD;
printf("%lld\n",ans);
return 0;
}
/*
C(a[i]+b[i]+a[j]+b[j],a[i]+a[j]):从(-a[i],-b[i]）走到(a[j],b[j])
*/ | codenet | -1 | 1,402 |
s971887031 | p04051 | 1,514,497,350 | cpp | Accepted | 324 | 127,488 | #include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int N;
int A[200010],B[200010] = {0};
ll mod = 1000000007;
ll dp[4010][4010] = {0};
ll ans = 0;
ll F[8010],R[8010];
ll pow_mod(ll a,ll b)
{
if(b == 0)return 1;
ll res = pow_mod(a * a % mod,b / 2);
if(b & 1)res = res * a % mod;
return res;
}
ll con(ll a,ll b)
{
return F[a] * R[b] % mod * R[a - b] % mod;
}
int main()
{
scanf("%d",&N);
for(int i = 0; i < N; i++)scanf("%d%d",A + i,B + i);
for(int i = 0; i < N; i++)
{
dp[2001 - A[i]][2001 - B[i]]++;
}
for(int i = 1; i <= 4001; i++)
{
for(int j = 1; j <= 4001; j++)
{
dp[i][j] = (dp[i][j] + dp[i - 1][j] + dp[i][j - 1]) % mod;
}
}
for(int i = 0; i < N; i++)
{
ans += dp[A[i] + 2001][B[i] + 2001];
ans %= mod;
}
/*
for(int i = 0; i < 8010; i++)
{
for(int j = 0; j <= i; j++)
{
if(j == 0)con[i][j] = 1;
else con[i][j] = (con[i - 1][j] + con[i - 1][j - 1]) % mod;
}
}
*/
F[0] = 1;
for(int i = 1; i < 8010; i++)F[i] = F[i - 1] * i % mod;
for(int i = 0; i < 8010; i++)R[i] = pow_mod(F[i],mod - 2);
for(int i = 0; i < N; i++)
{
ans -= con(A[i] * 2 + B[i] * 2,A[i] * 2);
ans = (ans + mod) % mod;
}
printf("%lld\n",ans * 500000004 % mod);
return 0;
}
| codenet | -1 | 1,408 |
s420516464 | p04051 | 1,494,731,853 | cpp | Accepted | 146 | 95,232 | #include<cstdio>
#include<cstring>
#include<algorithm>
#define N 2005
using namespace std;
const int mod = 1e9+7;
inline int read(){
int sum = 0, t = 1; char ch = getchar();
while(ch < '0' || ch > '9'){ if(ch == '-') t = -1; ch = getchar(); }
while(ch >= '0' && ch <= '9'){ sum = sum * 10 + ch - '0'; ch = getchar(); }
return sum * t;
}
int n;
int f[N<<1][N<<1];
int a[N<<1][N<<1];
int fac[N<<2], inv[N<<2];
void upd(int &x, int y){ x += y; if(x >= mod) x -= mod; }
int quick_mod(int x, int y){
int res = 1; x %= mod;
for(; y ; y >>= 1, x = 1LL * x * x % mod)
if(y & 1) res = 1LL * res * x % mod;
return res;
}
int C(int x, int y){ return x < y ? 0 : 1LL * fac[x] * inv[y] % mod * inv[x - y] % mod; }
int main(){
int ans = 0;
fac[0] = 1;
for(int i = 1; i < (N << 2); i++) fac[i] = 1LL * fac[i - 1] * i % mod;
inv[(N << 2) - 1] = quick_mod(fac[(N << 2) - 1], mod - 2);
for(int i = (N << 2) - 1; i ; i--) inv[i - 1] = 1LL * inv[i] * i % mod;
n = read();
for(int i = 1; i <= n; i++){
int A = read(), B = read();
upd(a[A + N][B + N], 1);
upd(f[N - A][N - B], 1);
upd(ans, mod - C(A + A + B + B, A + A));
}
for(int i = 0; i < (N << 1); i++)
for(int j = 0; j < (N << 1); j++){
upd(ans, 1LL * a[i][j] * f[i][j] % mod);
if(i + 1 < (N << 1)) upd(f[i + 1][j], f[i][j]);
if(j + 1 < (N << 1)) upd(f[i][j + 1], f[i][j]);
}
ans = 1LL * ans * 500000004 % mod;
printf("%d\n", ans);
}
| codenet | -1 | 1,414 |
s044546675 | p04051 | 1,581,671,086 | cpp | Accepted | 185 | 65,920 | #include <bits/stdc++.h>
using namespace std;
#define Pii pair<int, int>
#define ll long long
#define mod 1000000007
#define N 10001
#define S 2000
ll Qpow(ll x, ll n) {
ll s = 1;
while (n) {
if (n & 1) s = s * x % mod;
x = x * x % mod;
n >>= 1;
}
return s;
}
ll inv(ll x) { return Qpow(x, mod - 2); }
ll fac[N], ifac[N];
ll C(int x, int y) { return fac[x] * ifac[x - y] % mod * ifac[y] % mod; }
void Prepare() {
fac[0] = 1;
for (ll i = 1; i < N; i++) fac[i] = fac[i - 1] * i % mod;
ifac[N - 1] = inv(fac[N - 1]);
for (ll i = N - 1; i; i--) ifac[i - 1] = ifac[i] * i % mod;
}
Pii P[S * S];
int d[S << 1 | 1][S << 1 | 1], n;
int main() {
scanf("%d", &n);
for (int i = 1; i <= n; i++) scanf("%d%d", &P[i].first, &P[i].second);
Prepare();
for (int i = 1; i <= n; i++) d[S - P[i].first][S - P[i].second]++;
for (int dis = 1; dis <= S << 2; dis++)
for (int i = max(0, dis - (S << 1)); i <= min(S << 1, dis); i++) {
int j = dis - i;
if (i) d[i][j] = (d[i][j] + d[i - 1][j]) % mod;
if (j) d[i][j] = (d[i][j] + d[i][j - 1]) % mod;
}
ll ans = 0;
for (int i = 1; i <= n; i++) {
int x = P[i].first, y = P[i].second;
ans = (ans + d[x + S][y + S]) % mod;
ans = (ans - C(2 * x + 2 * y, 2 * x) + mod) % mod;
}
printf("%lld\n", ans * inv(2) % mod);
return 0;
} | codenet | -1 | 1,416 |
s625880692 | p04051 | 1,597,695,146 | cpp | Accepted | 158 | 67,828 | #include<bits/stdc++.h>
#define ll long long
#define ld long double
#define db double
#define pint pair<int,ll>
#define mk make_pair
#define pb push_back
#define eb emplace_back
#define ins insert
#define fi first
#define se second
#define Rep(x,y,z) for(int x=y;x<=z;x++)
#define Red(x,y,z) for(int x=y;x>=z;x--)
using namespace std;
const int MAXN=2e5+5,MAXM=4005,Mod=1e9+7,Inv=Mod+1>>1;
char buf[1<<12],*pp1=buf,*pp2=buf,nc;int ny;
inline char gc() {return pp1==pp2&&(pp2=(pp1=buf)+fread(buf,1,1<<12,stdin),pp1==pp2)?EOF:*pp1++;}
//inline char gc(){return getchar();}
inline int read(){
int x=0;for(ny=1;nc=gc(),(nc<48||nc>57)&&nc!=EOF;)if(nc==45)ny=-1;if(nc<0)return nc;
for(x=nc-48;nc=gc(),47<nc&&nc<58&&nc!=EOF;x=(x<<3)+(x<<1)+(nc^48));return x*ny;
}
int n,O,f[MAXM][MAXM],a[MAXN],b[MAXN],Fac[MAXN],iFac[MAXN];
inline int Fp(int x,int k){int ans=1;for(;k;k>>=1,x=1ll*x*x%Mod)if(k&1)ans=1ll*ans*x%Mod;return ans;}
int main(){
// freopen("std.in","r",stdin);
// freopen("std.out","w",stdout);
n=read(),O=2000;
Fac[0]=iFac[0]=1;Rep(i,1,8000)Fac[i]=1ll*Fac[i-1]*i%Mod,iFac[i]=Fp(Fac[i],Mod-2);
Rep(i,1,n)a[i]=read(),b[i]=read(),f[O-a[i]][O-b[i]]++;
Rep(i,0,4000)Rep(j,0,4000)f[i][j]=(0ll+(i?f[i-1][j]:0)+(j?f[i][j-1]:0)+f[i][j])%Mod;
int ans=0;Rep(i,1,n)ans=(ans+f[O+a[i]][O+b[i]])%Mod,ans=(ans-1ll*Fac[a[i]+b[i]<<1]*iFac[a[i]<<1]%Mod*iFac[b[i]<<1]%Mod+Mod)%Mod;
cout<<1ll*ans*Inv%Mod<<'\n';
return 0;
}
| codenet | -1 | 1,417 |
s722615422 | p04051 | 1,576,682,640 | cpp | Accepted | 191 | 65,280 | //Created Time:2019年12月18日 星期三 08时37分26秒
#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#define N 200005
#define M 4004
#define mod 1000000007
using namespace std;
int n;
int ifac[N], fac[N], f[M][M], cnt[M][M], x[N], y[N];
int read();
void init();
int quick_pow(int);
int C(int ,int);
int main(){
n = read(); int m = 2001; init();
for(int i = 1; i <= n; ++i){
x[i] = read(), y[i] = read();
f[m - x[i]][m - y[i]]++;
}
for(int i = 1; i <= m * 2; ++i)
for(int j = 1; j <= m * 2; ++j)
(f[i][j] += (f[i - 1][j] + f[i][j - 1]) % mod) %= mod;
int ans = 0;
for(int i = 1; i <= n; ++i){
(ans += f[x[i] + m][y[i] + m]) %= mod;
(ans += mod - C(x[i] * 2 + y[i] * 2, x[i] * 2)) %= mod;
}
cout << 1ll * ans * quick_pow(2) % mod << endl;;
return 0;
}
int read(){
int x = 0; char ch = getchar();
for(; !isdigit(ch); ch = getchar());
for(; isdigit(ch); ch = getchar()) x = (x << 1) + (x << 3) + (ch ^ 48);
return x;
}
void init(){
int m = 10000; fac[0] = ifac[0] = 1;
for(int i = 1; i <= m; ++i)
fac[i] = 1ll * fac[i - 1] * i % mod;
ifac[m] = quick_pow(fac[m]);
for(int i = m; i; --i)
ifac[i - 1] = 1ll * ifac[i] * i % mod;
return ;
}
int quick_pow(int x){
int sum = 1, y = mod - 2;
for(; y; y >>= 1, x = 1ll * x * x % mod) if(y & 1) sum = 1ll * sum * x % mod;
return sum;
}
int C(int x, int y){
return 1ll * fac[x] * ifac[y] % mod * ifac[x - y] % mod;
}
| codenet | -1 | 1,417 |
s601812761 | p04051 | 1,574,141,451 | cpp | Accepted | 174 | 96,384 | #include<bits/stdc++.h>
#define MAXN 200005
#define MAXM 4005
#define INF 1000000000
#define MOD 1000000007
#define INV 500000004
#define F first
#define S second
using namespace std;
typedef long long ll;
typedef pair<int,int> P;
const int offset=2000;
int n,a[MAXN],b[MAXN],fact[2*MAXM],invf[2*MAXM];
int dp[MAXM][MAXM],coef[MAXM][MAXM];
void add(int &a,int b) {a+=b; if(a>=MOD) a-=MOD;}
void dec(int &a,int b) {a-=b; if(a<0) a+=MOD;}
int pow_mod(int a,int i)
{
int s=1;
while(i)
{
if(i&1) s=1LL*s*a%MOD;
a=1LL*a*a%MOD;
i>>=1;
}
return s;
}
int comb(int n,int k)
{
if(n<k) return 0;
return 1LL*fact[n]*invf[k]%MOD*invf[n-k]%MOD;
}
int main()
{
fact[0]=invf[0]=1;
for(int i=1;i<=8000;i++) fact[i]=1LL*fact[i-1]*i%MOD;
invf[8000]=pow_mod(fact[8000],MOD-2);
for(int i=7999;i>=1;i--) invf[i]=1LL*invf[i+1]*(i+1)%MOD;
scanf("%d",&n);
for(int i=1;i<=n;i++)
{
scanf("%d%d",&a[i],&b[i]);
add(dp[offset-a[i]][offset-b[i]],1);
add(coef[offset+a[i]][offset+b[i]],1);
}
int ans=0;
for(int i=0;i<=4000;i++)
for(int j=0;j<=4000;j++)
{
add(ans,1LL*coef[i][j]*dp[i][j]%MOD);
add(dp[i+1][j],dp[i][j]);
add(dp[i][j+1],dp[i][j]);
}
for(int i=1;i<=n;i++) dec(ans,comb(2*a[i]+2*b[i],2*a[i]));
ans=1LL*ans*INV%MOD;
printf("%d\n",ans);
return 0;
}
| codenet | -1 | 1,419 |
s601812761 | p04051 | 1,574,141,451 | cpp | Accepted | 174 | 96,384 | #include<bits/stdc++.h>
#define MAXN 200005
#define MAXM 4005
#define INF 1000000000
#define MOD 1000000007
#define INV 500000004
#define F first
#define S second
using namespace std;
typedef long long ll;
typedef pair<int,int> P;
const int offset=2000;
int n,a[MAXN],b[MAXN],fact[2*MAXM],invf[2*MAXM];
int dp[MAXM][MAXM],coef[MAXM][MAXM];
void add(int &a,int b) {a+=b; if(a>=MOD) a-=MOD;}
void dec(int &a,int b) {a-=b; if(a<0) a+=MOD;}
int pow_mod(int a,int i)
{
int s=1;
while(i)
{
if(i&1) s=1LL*s*a%MOD;
a=1LL*a*a%MOD;
i>>=1;
}
return s;
}
int comb(int n,int k)
{
if(n<k) return 0;
return 1LL*fact[n]*invf[k]%MOD*invf[n-k]%MOD;
}
int main()
{
fact[0]=invf[0]=1;
for(int i=1;i<=8000;i++) fact[i]=1LL*fact[i-1]*i%MOD;
invf[8000]=pow_mod(fact[8000],MOD-2);
for(int i=7999;i>=1;i--) invf[i]=1LL*invf[i+1]*(i+1)%MOD;
scanf("%d",&n);
for(int i=1;i<=n;i++)
{
scanf("%d%d",&a[i],&b[i]);
add(dp[offset-a[i]][offset-b[i]],1);
add(coef[offset+a[i]][offset+b[i]],1);
}
int ans=0;
for(int i=0;i<=4000;i++)
for(int j=0;j<=4000;j++)
{
add(ans,1LL*coef[i][j]*dp[i][j]%MOD);
add(dp[i+1][j],dp[i][j]);
add(dp[i][j+1],dp[i][j]);
}
for(int i=1;i<=n;i++) dec(ans,comb(2*a[i]+2*b[i],2*a[i]));
ans=1LL*ans*INV%MOD;
printf("%d\n",ans);
return 0;
}
| codenet | -1 | 1,419 |
s462801030 | p04051 | 1,595,529,846 | cpp | Accepted | 212 | 146,456 | #include <iostream>
#include <cstring>
#include <cstdio>
#define LL long long
#define Maxn 200010
#define Maxk 8010
using namespace std;
const LL INF = 1e9, D = 2001, MOD = 1e9 + 7;
inline int read() {
int x = 0, f = 1;
char c = getchar();
while(c < '0' || c > '9') {
if(c == '-') f = -1;
c = getchar();
}
while('0' <= c && c <= '9') {
x = x * 10 + c - '0';
c = getchar();
}
return x * f;
}
int n, a[Maxn], b[Maxn];
LL f[Maxk][Maxk], fac[Maxk], facinv[Maxk], ans;
LL Pow(LL a, LL b) {
LL ans = 1, base = a;
while(b) {
if(b & 1) ans = ans * base % MOD;
base = base * base % MOD;
b >>= 1;
}
return ans;
}
void pre() {
fac[0] = facinv[0] = 1;
for(int i = 1; i < Maxk; ++i) fac[i] = fac[i - 1] * i % MOD;
facinv[Maxk - 1] = Pow(fac[Maxk - 1], MOD - 2);
for(int i = Maxk - 2; i; --i) facinv[i] = facinv[i + 1] * (i + 1) % MOD;
}
LL C(LL a, LL b) {
return fac[a] * facinv[b] % MOD * facinv[a - b] % MOD;
}
int main() {
n = read();
pre();
for(int i = 1; i <= n; ++i) {
a[i] = read(); b[i] = read();
++f[D - a[i]][D - b[i]];
}
for(int i = 1; i <= 4003; ++i)
for(int j = 1; j <= 4003; ++j)
f[i][j] += f[i - 1][j] + f[i][j - 1], f[i][j] %= MOD;
for(int i = 1; i <= n; ++i) ans = (ans + f[a[i] + D][b[i] + D]) % MOD;
for(int i = 1; i <= n; ++i) ans -= C(a[i] * 2 + b[i] * 2, a[i] * 2), ans %= MOD;
ans *= Pow(2, MOD - 2);
cout << (ans % MOD + MOD) % MOD << endl;
return 0;
} | codenet | -1 | 1,422 |
s601670334 | p04051 | 1,539,727,786 | cpp | Accepted | 195 | 196,736 | #include <iostream>
#include <cstring>
#include <cstdio>
#include <cctype>
#define int long long
const int mod = 1e9 + 7;
inline void read(int & x)
{
x = 0;
int k = 1;
char c = getchar();
while (!isdigit(c))
if (c == '-') c = getchar(), k = -1;
else c = getchar();
while (isdigit(c))
x = (x << 1) + (x << 3) + (c ^ 48),
c = getchar();
x *= k;
}
inline int min(int a, int b) { return a > b ? b : a; }
int n, ans = 0, O = 2001;
int a[201010], b[201010];
int d[4050][4050];
int dp[4050][4050];
int fac[40005];
int inv[40005];
inline int ksm(int a, int b)
{
int ans = 1;
while (b)
{
if (b & 1) ans = (ans * a) % mod;
b >>= 1, a = (a * a) % mod;
}
return ans;
}
void DP_it(void)
{
for (int i = 1; i <= 4030; ++i)
for (int j = 1; j <= 4030; ++j)
dp[i][j] = (dp[i - 1][j] + dp[i][j - 1] + d[i][j]) % mod;
}
inline int C(int a, int b) { return ((fac[a] * inv[b]) % mod * inv[a - b]) % mod; }
signed main()
{
fac[0] = 1; inv[0] = 1;
for (int i = 1; i <= 40000; ++i) fac[i] = (1LL * fac[i - 1] * i) % mod;
inv[40000] = ksm(fac[40000], mod - 2);
for (int i = 39999; i >= 1; --i) inv[i] = (inv[i + 1] * (i + 1)) % mod;
read(n);
for (int i = 1; i <= n; ++i) read(a[i]), read(b[i]), ++d[O - a[i]][O - b[i]];
DP_it();
for (int i = 1; i <= n; ++i)
ans =((ans + dp[O + a[i]][O + b[i]] - C((a[i] + b[i]) << 1, a[i] + a[i])) % mod + mod) % mod;
std::cout << (ans * ksm(2, mod - 2)) % mod;
} | codenet | -1 | 1,422 |
s315911951 | p04051 | 1,566,975,656 | cpp | Accepted | 227 | 129,024 | #include <iostream>
#define llint long long
#define mod 1000000007
using namespace std;
llint n;
llint a[200005], b[200005];
llint dp[4009][4009];
const int Zero = 2004;
const int FACT_MAX = 10005;
llint fact[FACT_MAX], fact_inv[FACT_MAX];
llint modpow(llint a, llint n)
{
if(n == 0) return 1;
if(n % 2){
return ((a%mod) * (modpow(a, n-1)%mod)) % mod;
}
else{
return modpow((a*a)%mod, n/2) % mod;
}
}
void make_fact()
{
llint val = 1;
fact[0] = 1;
for(int i = 1; i < FACT_MAX; i++){
val *= i;
val %= mod;
fact[i] = val;
}
fact_inv[FACT_MAX-1] = modpow(fact[FACT_MAX-1], mod-2);
for(int i = FACT_MAX-2; i >= 0; i--){
fact_inv[i] = fact_inv[i+1] * (i+1) % mod;
}
}
llint comb(llint n, llint k)
{
llint ret = 1;
ret *= fact[n];
ret *= fact_inv[k], ret %= mod;
ret *= fact_inv[n-k], ret %= mod;
return ret;
}
int main(void)
{
make_fact();
cin >> n;
for(int i = 1; i <= n; i++) cin >> a[i] >> b[i];
for(int i = 1; i <= n; i++) dp[Zero+a[i]][Zero+b[i]]++;
for(int i = Zero+2000; i >= Zero-2000; i--){
for(int j = Zero+2000; j >= Zero-2000; j--){
dp[i][j] += dp[i+1][j] + dp[i][j+1];
dp[i][j] %= mod;
}
}
llint ans = 0;
for(int i = 1; i <= n; i++){
ans += dp[Zero-a[i]][Zero-b[i]];
ans %= mod;
}
for(int i = 1; i <= n; i++){
ans += mod - comb(2*(a[i]+b[i]), 2*a[i]);
ans %= mod;
}
ans *= modpow(2, mod-2), ans %= mod;
cout << ans << endl;
return 0;
} | codenet | -1 | 1,423 |
s361697414 | p04051 | 1,476,341,379 | cpp | Accepted | 384 | 139,888 | #include <iostream>
#include <fstream>
#include <set>
#include <map>
#include <string>
#include <vector>
#include <bitset>
#include <algorithm>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <cassert>
#include <queue>
#define mp make_pair
#define pb push_back
typedef long long ll;
typedef long double ld;
using namespace std;
const ll MOD = 1e9 + 7;
ll pw(ll a, ll b) {
ll ans = 1;
while (b) {
while (!(b & 1))
b >>= 1, a = (a * a) % MOD;
ans = (ans * a) % MOD;
--b;
}
return ans;
}
ll fc[10000];
ll bfc[10000];
void init() {
fc[0] = 1;
for (int i = 1; i < 10000; ++i)
fc[i] = (fc[i - 1] * i) % MOD;
for (int i = 0; i < 10000; ++i)
bfc[i] = pw(fc[i], MOD - 2);
}
ll cnk(int n, int k) {
return fc[n] * bfc[k] % MOD * bfc[n - k] % MOD;
}
const int MX = 2100;
int n;
ll arr[MX * 2][MX * 2];
int main() {
init();
scanf("%d", &n);
ll ans = 0;
vector<pair<int, int> > vv;
for (int i = 0; i < n; ++i) {
int a, b;
scanf("%d%d", &a, &b);
++arr[MX - a][MX - b];
vv.push_back(make_pair(a, b));
ans = (ans + MOD - cnk(2 * a + 2 * b, 2 * b)) % MOD;
}
for (int i = 1; i < MX * 2; ++i)
for (int j = 1; j < MX * 2; ++j)
arr[i][j] = (arr[i][j] + arr[i - 1][j] + arr[i][j - 1]) % MOD;
for (int i = 0; i < (int)vv.size(); ++i) {
ans = (ans + arr[vv[i].first + MX][vv[i].second + MX]) % MOD;
}
ans = (ans * pw(2, MOD - 2)) % MOD;
cout << ans << "\n";
return 0;
}
| codenet | -1 | 1,423 |
s488647272 | p04051 | 1,573,418,074 | cpp | Accepted | 189 | 130,944 | #pragma GCC optimize("Ofast,inline", 3)
#include<bits/stdc++.h>
#define il inline
#define rg register
#define gi read<int>
#define int long long
using namespace std;
const int O = 2e5 + 10, lim = 2010, mod = 1e9 + 7, Lim = 2020;
template<class TT>
il TT read() {
TT o = 0, fl = 1; char ch = getchar();
while (!isdigit(ch) && ch != '-') ch = getchar();
if (ch == '-') fl = -1, ch = getchar();
while (isdigit(ch)) o = o * 10 + ch - '0', ch = getchar();
return fl * o;
}
int n, a[O], b[O], dp[Lim << 1][Lim << 1], fac[Lim << 2], inv[Lim << 2], ans;
//il void pls(int & x, int y) {x += y; if (x >= mod) x -= mod;}
il int C(int x, int y) {return 1ll * fac[y] * inv[x] % mod * inv[y - x] % mod;}
signed main() {
fac[0] = inv[1] = 1; for (int i = 1; i <= lim << 2; ++i) fac[i] = 1ll * fac[i - 1] * i % mod; for (int i = 2; i <= lim << 2; ++i) inv[i] = 1ll * (mod - mod / i) * inv[mod % i] % mod; for (int i = 2; i <= lim << 2; ++i) inv[i] = 1ll * inv[i] * inv[i - 1] % mod;
n = gi();
for (int i = 1; i <= n; ++i) {
a[i] = gi(), b[i] = gi();
++dp[lim - a[i]][lim - b[i]];
}
for (int i = 1; i <= lim + 1 << 1; ++i)
for (int j = 1; j <= lim + 1 << 1; ++j)
dp[i][j] = ((dp[i][j] + dp[i][j - 1]) % mod + dp[i - 1][j]) % mod;
for (int i = 1; i <= n; ++i) {
(ans += dp[lim + a[i]][lim + b[i]]) %= mod;
(ans += mod - C(a[i] << 1, a[i] + b[i] << 1)) %= mod;
}
printf("%lld", 1ll * ans * inv[2] % mod);
return 0;
} | codenet | -1 | 1,424 |
s772632850 | p04051 | 1,515,032,111 | cpp | Accepted | 128 | 64,384 | #include<cstdio>
inline int read()
{
int x;char c;
while((c=getchar())<'0'||c>'9');
for(x=c-'0';(c=getchar())>='0'&&c<='9';)x=x*10+c-'0';
return x;
}
const int MOD=1e9+7;
struct mint{int x;mint(int x=0):x(x){}};
inline mint operator+ (mint a,mint b){return a.x+b.x<MOD?a.x+b.x:a.x+b.x-MOD;}
inline mint operator- (mint a){return MOD-a.x;}
inline mint operator- (mint a,mint b){return a+-b;}
inline mint operator* (mint a,mint b){return 1LL*a.x*b.x%MOD;}
inline mint operator<< (mint x,int y){mint r=1;for(;y;y>>=1,x=x*x)if(y&1)r=r*x;return r;}
inline mint operator~ (mint x){return x<<MOD-2;}
inline mint operator/ (mint a,mint b){return a*~b;}
inline mint&operator+= (mint&a,mint b){return a=a+b;}
inline mint&operator-= (mint&a,mint b){return a=a-b;}
inline mint&operator*= (mint&a,mint b){return a=a*b;}
inline mint&operator<<=(mint&x,int y){return x=x<<y;}
inline mint&operator/= (mint&a,mint b){return a=a/b;}
#define MN 200000
#define MX 2001
mint f[MX*2][MX*2],F[MX*4+5],R[MX*4+5],ans;
int a[MN+5],b[MN+5];
inline mint C(int n,int m){return F[n]*R[m]*R[n-m];}
int main()
{
int n=read(),i,j;
for(i=1;i<=n;++i)a[i]=read(),b[i]=read(),f[MX-a[i]][MX-b[i]]+=1;
for(i=1;i<MX*2;++i)for(j=1;j<MX*2;++j)f[i][j]+=f[i-1][j]+f[i][j-1];
for(F[0]=i=1;i<=MX*4;++i)F[i]=F[i-1]*i;
for(R[i=MX*4]=~F[MX*4];i--;)R[i]=R[i+1]*(i+1);
for(i=1;i<=n;++i)ans+=f[MX+a[i]][MX+b[i]]-C(a[i]+b[i]<<1,a[i]<<1);
printf("%d",ans/2);
} | codenet | -1 | 1,424 |
s062055886 | p04051 | 1,489,332,286 | cpp | Accepted | 153 | 65,664 | #include<set>
#include<map>
#include<cmath>
#include<queue>
#include<bitset>
#include<string>
#include<cstdio>
#include<cctype>
#include<cassert>
#include<cstdlib>
#include<cstring>
#include<sstream>
#include<iostream>
#include<algorithm>
#define For(i,x,y) for (int i=x;i<y;i++)
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define dprintf(...) fprintf(stderr,__VA_ARGS__)
using namespace std;
typedef long long ll;
typedef double db;
typedef pair<int,int> pii;
typedef vector<int> Vi;
int IN(){
int c,f,x;
while (!isdigit(c=getchar())&&c!='-');c=='-'?(f=1,x=0):(f=0,x=c-'0');
while (isdigit(c=getchar())) x=(x<<1)+(x<<3)+c-'0';return !f?x:-x;
}
const int N=200000+19;
const int M=2000+19;
const int S=2001;
const int p=1e9+7;
int A[N],B[N];
int f[2*M][2*M],fac[4*M],inv[4*M];
int n,res;
int Pow(int a,int b){
int res=1;
for (;b;b>>=1,a=1ll*a*a%p) if (b&1) res=1ll*res*a%p;
return res;
}
int C(int n,int m){
return 1ll*fac[n]*inv[m]%p*inv[n-m]%p;
}
int main(){
fac[0]=1;
For(i,1,4*M) fac[i]=1ll*fac[i-1]*i%p;
inv[4*M-1]=Pow(fac[4*M-1],p-2);
for (int i=4*M-1;i;i--) inv[i-1]=1ll*inv[i]*i%p;
n=IN();
For(i,1,n+1){
A[i]=IN(),B[i]=IN();
f[-A[i]+S][-B[i]+S]++;
}
For(i,1,2*M) For(j,1,2*M){
f[i][j]=(0ll+f[i][j]+f[i][j-1]+f[i-1][j])%p;
}
For(i,1,n+1){
res=(res+f[A[i]+S][B[i]+S])%p;
res=(res-C(2*A[i]+2*B[i],2*A[i])+p)%p;
}
printf("%d\n",1ll*res*Pow(2,p-2)%p);
} | codenet | -1 | 1,426 |
s905452247 | p04051 | 1,468,722,152 | cpp | Accepted | 336 | 67,072 | #include<stdio.h>
#include<algorithm>
using namespace std;
long long mod=1000000007;
int p[210000];
int q[210000];
long long inv[11000];
long long fact[11000];
long long factinv[11000];
int M=10000;
inline long long C(int a,int b){
return fact[a]*factinv[b]%mod*factinv[a-b]%mod;
}
//int T[2100][2100];
//int Y[2100][2100];
long long d2=500000004;
int dp[4100][4100];
int main(){
int a;scanf("%d",&a);
for(int i=0;i<a;i++){
scanf("%d%d",p+i,q+i);
}
long long ret=0;
inv[1]=fact[0]=factinv[0]=1;
for(int i=1;i<M;i++)fact[i]=fact[i-1]*i%mod;
for(int i=2;i<M;i++)inv[i]=(mod-(mod/i)*inv[mod%i]%mod)%mod;
for(int i=1;i<M;i++)factinv[i]=factinv[i-1]*inv[i]%mod;
/* for(int i=0;i<a;i++){
T[p[i]][0]++;
T[p[i]][q[i]]--;
Y[q[i]][0]++;
Y[q[i]][p[i]]--;
}
for(int i=0;i<2100;i++){
for(int j=1;j<2100;j++){
T[i][j]+=T[i][j-1];
Y[i][j]+=Y[i][j-1];
}
}*/
int D=2050;
for(int i=0;i<a;i++){
dp[D+p[i]][D+q[i]]++;
}
for(int i=D+2010;i>=0;i--){
for(int j=D+2010;j>=0;j--){
if(dp[i][j]>=mod)dp[i][j]-=mod;
if(i)dp[i-1][j]+=dp[i][j];
if(j)dp[i][j-1]+=dp[i][j];
}
}
for(int i=0;i<a;i++){
//printf("%d: %lld\n",i,dp[D-p[i]][D-q[i]]);
ret=(ret+dp[D-p[i]][D-q[i]])%mod;
}
//printf("%lld\n",ret);
for(int i=0;i<a;i++){
// printf("%d: %lld\n",i,C(p[i]*2+q[i]*2,p[i]*2));
ret=(ret+mod-C(p[i]*2+q[i]*2,p[i]*2))%mod;
}
//printf("%lld\n",ret);
ret=ret*d2%mod;
printf("%lld\n",ret);
} | codenet | -1 | 1,427 |
s847409223 | p04051 | 1,569,628,294 | cpp | Accepted | 101 | 128,768 | #include<bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
bool chkmax(int &x,int y){return x<y?x=y,true:false;}
bool chkmin(int &x,int y){return x>y?x=y,true:false;}
int readint(){
int x=0,f=1; char ch=getchar();
while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
return x*f;
}
const int cys=1000000007;
int n,maxa;
ll a[200005],b[200005],fac[8005],inv[8005],d[4005][4005];
ll mod(ll x){return x>=cys?x-cys:x;}
ll qpow(ll x,ll p){
ll ret=1;
for(;p;p>>=1,x=x*x%cys) if(p&1) ret=ret*x%cys;
return ret;
}
int main(){
n=readint();
for(int i=1;i<=n;i++) a[i]=readint(),b[i]=readint(),chkmax(maxa,max(a[i],b[i]));
fac[0]=inv[0]=1;
for(int i=1;i<=4*maxa;i++) fac[i]=fac[i-1]*i%cys;
inv[4*maxa]=qpow(fac[4*maxa],cys-2);
for(int i=4*maxa-1;i>=1;i--) inv[i]=inv[i+1]*(i+1)%cys;
for(int i=1;i<=n;i++) d[-a[i]+maxa][-b[i]+maxa]++;
for(int i=0;i<=2*maxa;i++){
for(int j=0;j<=2*maxa;j++){
if(i) d[i][j]=mod(d[i][j]+d[i-1][j]);
if(j) d[i][j]=mod(d[i][j]+d[i][j-1]);
}
}
ll ans=0;
for(int i=1;i<=n;i++) ans=mod(ans+d[a[i]+maxa][b[i]+maxa]);
for(int i=1;i<=n;i++) ans=mod(ans+cys-fac[2*a[i]+2*b[i]]*inv[2*a[i]]%cys*inv[2*b[i]]%cys);
printf("%lld\n",ans*((cys+1)/2)%cys);
return 0;
} | codenet | -1 | 1,430 |
s844869351 | p04051 | 1,590,811,211 | cpp | Accepted | 258 | 196,352 | #include <bits/stdc++.h>
typedef long long int ll;
typedef long double ld;
#define pb push_back
#define pii pair < ll , ll >
#define F first
#define S second
#define endl '\n'
#define int long long
#define sync ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math")
#define kill(x) return cout<<x<<'\n', 0;
using namespace std;
const int N=4e3+10,mod=1e9+7,M=2e5+100;
ll dp[N][N];
ll val[N][N];
ll a[M],b[M];
ll power(ll n,ll k){
if (k==0) return 1;
if (k%2==1){
ll x=power(n,k/2);
return x*x%mod*n%mod;
}
ll x=power(n,k/2);
return x*x%mod;
}
ll fac[M],fm[M];
ll ent(ll k,ll n){
if (k==0 || k==n) return 1;
if (k<0 || k>n) return 0;
return (fac[n]*fm[k]%mod)*fm[n-k]%mod;
}
int32_t main(){
fac[0]=1;
for (int i=1;i<M;i++){
fac[i]=fac[i-1]*i%mod;
fm[i]=power(fac[i],mod-2);
}
ll n;
cin >> n;
for (int i=1;i<=n;i++) cin >> a[i] >> b[i];
for (int i=1;i<=n;i++){
val[-a[i]+N/2][-b[i]+N/2]++;
}
ll ans=0;
for (int i=1;i<N;i++){
for (int j=1;j<N;j++){
dp[i][j]+=dp[i][j-1]+dp[i-1][j]+val[i][j];
dp[i][j]%=mod;
}
}
for (int i=1;i<=n;i++){
ans+=dp[a[i]+N/2][b[i]+N/2];
ans-=ent(2*a[i],2*a[i]+2*b[i]);
ans+=mod;
ans%=mod;
}
cout << ans*power(2,mod-2)%mod << endl;
}
| codenet | -1 | 1,431 |
s850648336 | p04051 | 1,503,250,838 | cpp | Accepted | 557 | 127,600 | #include <cstdio>
#include <cassert>
#include <vector>
using namespace std;
long long tbl[4010][4010];
long long fact[8010];
long long iFact[8010];
long long mod=1000000007;
long long poww(long long x,long long y) {
long long res = 1;
while(y)
{
if(y & 1) res = (res * x) % mod;
x = x * x % mod;
y = y >> 1;
}
return res;
//if (x==0) return 1;
//if (x==1) return b;
//long long tmp = poww(b,x/2);
//tmp=(tmp*tmp)%mod;
//if (x%2) {
//return (tmp*b)%mod;
//} else {
//return tmp;
//}
}
int main() {
int n;
scanf("%d",&n);
fact[0]=1;
for (int i=1;i<8010;i++) {
fact[i]=fact[i-1]*i;
fact[i]%=mod;
iFact[i]=poww(fact[i],mod-2);
//printf("%lld\n",fact[i]);
}
//printf("%lld\n",iFact[2]);
int a,b;
long long ans=0;
//int c,d;
//scanf("%d%d%d%d",&a,&b,&c,&d);
//printf("%d %d %lld %lld %lld\n",a+c,b+d,fact[a+b+c+d],iFact[a+c],iFact[b+d]);
vector<pair<int,int>> ttt;
for (int i=0;i<n;i++) {
scanf("%d%d",&a,&b);
ans-=(((fact[2*a+2*b]*iFact[2*a])%mod)*iFact[2*b])%mod;
ans%=mod;
//printf("%lld\n",(((fact[2*a+2*b]*iFact[2*a])%mod)*iFact[2*b])%mod);
tbl[2001-a][2001-b]++;
ttt.push_back({2001+a,2001+b});
}
for (int i=1;i<4010;i++) {
for (int j=1;j<4010;j++) {
tbl[i][j]+=(tbl[i-1][j]+tbl[i][j-1])%mod;
tbl[i][j]%=mod;
}
}
for (int i=0;i<n;i++) {
ans+=tbl[ttt[i].first][ttt[i].second];
ans%=mod;
}
ans*=iFact[2];
ans%=mod;
printf("%lld\n",ans);
return 0;
}
| codenet | -1 | 1,432 |
s093460944 | p04051 | 1,469,990,805 | cpp | Accepted | 1,434 | 252,288 | #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> ii;
typedef vector<int> vi;
typedef long double ld;
#define fi first
#define se second
#define pb push_back
#define mp make_pair
const int MOD = 1e9 + 7;
const int N = 2001;
int a[200001];
int b[200001];
int dp[8001][8001];
int choose(int a, int b)
{
if(a < b) return 0;
if(dp[a][b] != -1) return dp[a][b];
if(b == 0) return 1;
if(b == 1) return a;
dp[a][b] = (ll(choose(a - 1, b)) + ll(choose(a - 1, b - 1)))%MOD;
return dp[a][b];
}
ll modpow(ll a, ll b)
{
ll r = 1;
while(b)
{
if(b&1) r = (r*a)%MOD;
a = (a*a)%MOD;
b>>=1;
}
return r;
}
int main()
{
ios_base::sync_with_stdio(0); cin.tie(0);
int n;
cin >> n;
for(int i = 0; i < n; i++)
{
cin >> a[i] >> b[i];
}
for(int i = 0; i < n; i++)
{
dp[-a[i]+N][-b[i]+N]++;
//dp2[a[i]+N][b[i]+N]++;
}
for(int i = 1; i <= 4010; i++)
{
for(int j = 1; j <= 4010; j++)
{
dp[i][j] = (ll(dp[i][j]) + ll(dp[i - 1][j]) + ll(dp[i][j - 1]))%MOD;
}
}
ll ans = 0;
ll ans2 = 0;
for(int i = 0; i < n; i++)
{
ans += dp[a[i]+N][b[i]+N];
ans %= MOD;
}
memset(dp, -1, sizeof(dp));
for(int i = 0; i < n; i++)
{
ans2 += choose(2*(a[i]+b[i]), 2*b[i]);
ans2 %= MOD;
}
//cout << ans << ' ' << ans2 << endl;
ans = (ans - ans2)%MOD;
if(ans < 0) ans += MOD;
ans = (ans*modpow(2, MOD - 2))%MOD;
if(ans < 0) ans += MOD;
cout << ans;
return 0;
}
| codenet | -1 | 1,436 |
s534737613 | p04051 | 1,523,222,233 | cpp | Accepted | 78 | 75,008 | #include <bits/stdc++.h>
using namespace std;
typedef long long LL;
const int RLEN=1<<18|1;
inline char nc() {
static char ibuf[RLEN],*ib,*ob;
(ib==ob) && (ob=(ib=ibuf)+fread(ibuf,1,RLEN,stdin));
return (ib==ob) ? -1 : *ib++;
}
inline int rd() {
char ch=nc(); int i=0,f=1;
while(!isdigit(ch)) {if(ch=='-')f=-1; ch=nc();}
while(isdigit(ch)) {i=(i<<1)+(i<<3)+ch-'0'; ch=nc();}
return i*f;
}
const int mod=1e9+7;
inline int add(int x,int y) {return (x+y>=mod) ? (x+y-mod) : (x+y);}
inline int dec(int x,int y) {return (x-y<0) ? (x-y+mod) : (x-y);}
inline int mul(int x,int y) {return (LL)x*y%mod;}
inline int power(int a,int b,int rs=1) {
for(;b;b>>=1,a=mul(a,a)) if(b&1) rs=mul(rs,a);
return rs;
}
const int N=2e5+50, M=8e3+50;
int n,A[N],B[N],fac[M],ifac[M],f[4500][4500];
inline int& F(int a,int b) {return f[a+2003][b+2003];}
inline int C(int a,int b) {return mul(fac[a], mul(ifac[b], ifac[a-b]));}
int main() {
fac[0]=1;
for(int i=1;i<M;i++) fac[i]=mul(fac[i-1],i);
ifac[M-1]=power(fac[M-1],mod-2);
for(int i=M-2;~i;i--) ifac[i]=mul(ifac[i+1],i+1);
n=rd();
for(int i=1;i<=n;i++) A[i]=rd(), B[i]=rd(), F(-A[i],-B[i])++;//, cerr<<A[i]<<" "<<B[i]<<endl;
for(int i=-2000;i<=2000;++i)
for(int j=-2000;j<=2000;++j) {
F(i,j)=add(F(i,j),F(i-1,j));
F(i,j)=add(F(i,j),F(i,j-1));
}
int ans=0;
for(int i=1;i<=n;i++) ans=add(ans,F(A[i],B[i])), ans=dec(ans,C(2*A[i]+2*B[i],2*B[i])); cout<<mul(ans,(mod+1)/2);
} | codenet | -1 | 1,438 |
s098662004 | p04051 | 1,586,099,610 | cpp | Accepted | 221 | 128,640 | #include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
typedef long long ll;
inline ll read(){
ll f=1,res=0;char c=getchar();
while(c<'0'||c>'9') {if(c=='-')f=-1;c=getchar();}
while(c>='0'&&c<='9'){res=res*10+c-'0',c=getchar();}
return f*res;
}
const ll mod=1e9+7;
const int maxn=2e5+5;
const int maxm=8005;
ll fac[maxm]; //阶乘
ll inv[maxm]; //逆元
ll a[maxn],b[maxn],n,ans;
ll f[maxm/2][maxm/2],base=maxm/4;
const ll inv2=500000004;
ll quickMod(ll a,ll b){
ll ans=1;
while(b){
if(b&1) ans=ans*a%mod;
a=a*a%mod;
b>>=1;
}
return ans;
}
void getFac(){
fac[0]=inv[0]=1;
for(int i=1;i<=maxm;i++){
fac[i]=fac[i-1]*i%mod;
inv[i]=quickMod(fac[i],mod-2); //表示i的阶乘的逆元
}
}
ll getC(ll n,ll m){
return fac[n]*inv[n-m]%mod*inv[m]%mod;//C(n,m) = n!/((n-m)!*m!) % (1e9+7)
}
int main(){
// freopen("math.in","r",stdin);
// freopen("math.out","w",stdout);
getFac();
n=read();
for(int i=1;i<=n;i++) a[i]=read(),b[i]=read(),f[base-a[i]][base-b[i]]++;
for(int i=1;i<=maxm/2-1;i++){
for(int j=1;j<=maxm/2-1;j++){
f[i][j]=(f[i][j]+(f[i-1][j]+f[i][j-1])%mod)%mod;
// printf("%d %d %lld\n",i,j,f[i][j]);
}//cout<<"orz"<<" "<<i;
}
ans=0;
for(int i=1;i<=n;i++){
ans=(ans+f[base+a[i]][base+b[i]])%mod;
ans=(ans-getC(2*a[i]+2*b[i],2*a[i]))%mod;
}
ans=(ans+mod)%mod;
ans=ans*inv2%mod;
printf("%lld",ans);
return 0;
} | codenet | -1 | 1,440 |
s089984773 | p04051 | 1,543,618,754 | cpp | Accepted | 242 | 222,976 | #include <cstdio>
#include <algorithm>
int read()
{
int x=0,f=1;
char ch=getchar();
while((ch<'0')||(ch>'9'))
{
if(ch=='-')
{
f=-f;
}
ch=getchar();
}
while((ch>='0')&&(ch<='9'))
{
x=x*10+ch-'0';
ch=getchar();
}
return x*f;
}
const int maxn=200000;
const int maxm=2001;
const int maxk=maxm<<1;
const int mod=1000000007;
int n,x[maxn+10],y[maxn+10],mp[maxk+10][maxk+10],f[maxk+10][maxk+10],C[maxk*2+10][maxk+10];
int main()
{
n=read();
for(int i=1; i<=n; ++i)
{
int a=read(),b=read();
++mp[maxm-a][maxm-b];
x[i]=a;
y[i]=b;
}
C[0][0]=1;
for(int i=1; i<=maxk*2; ++i)
{
C[i][0]=C[i-1][0];
for(int j=1; (j<=i)&&(j<=maxk); ++j)
{
C[i][j]=C[i-1][j]+C[i-1][j-1];
if(C[i][j]>=mod)
{
C[i][j]-=mod;
}
}
}
for(int i=1; i<=maxk; ++i)
{
for(int j=1; j<=maxk; ++j)
{
f[i][j]=mp[i][j]+f[i-1][j]+f[i][j-1];
if(f[i][j]>=mod)
{
f[i][j]-=mod;
}
}
}
int ans=0;
for(int i=1; i<=n; ++i)
{
ans+=f[x[i]+maxm][y[i]+maxm];
if(ans>=mod)
{
ans-=mod;
}
ans-=C[(x[i]+y[i])<<1][x[i]<<1];
if(ans<0)
{
ans+=mod;
}
}
ans=1ll*ans*((mod+1)/2)%mod;
printf("%d\n",ans);
return 0;
}
| codenet | -1 | 1,440 |
s527028927 | p04051 | 1,514,690,547 | cpp | Accepted | 260 | 189,440 | #include <cstdio>
#include <iostream>
#include <algorithm>
#include <string>
#include <cstring>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <cmath>
#include <iomanip>
#include <cassert>
#include <bitset>
using namespace std;
typedef pair<int, int> P;
#define rep(i, n) for (int i=0; i<(n); i++)
#define all(c) (c).begin(), (c).end()
#define uniq(c) c.erase(unique(all(c)), (c).end())
#define index(xs, x) (int)(lower_bound(all(xs), x) - xs.begin())
#define _1 first
#define _2 second
#define pb push_back
#define INF 1145141919
#define MOD 1000000007
inline void add(int &x, int v) { x += v; if (x >= MOD) x -= MOD; }
int N;
int A[200000], B[200000];
int nCr[8001][4001];
int T[4002][4002];
signed main() {
ios::sync_with_stdio(false); cin.tie(0);
nCr[0][0] = 1;
for (int i=1; i<=8000; i++) {
nCr[i][0] = 1;
for (int j=1; j<=min(i, 4000); j++) {
nCr[i][j] = nCr[i-1][j-1] + nCr[i-1][j];
if (nCr[i][j] >= MOD) nCr[i][j] -= MOD;
}
}
cin >> N;
rep(i, N) {
cin >> A[i] >> B[i];
T[2000-A[i]][2000-B[i]]++;
}
for (int i=0; i<=4000; i++) {
for (int j=0; j<=4000; j++) {
add(T[i+1][j], T[i][j]);
add(T[i][j+1], T[i][j]);
}
}
int s = 0;
rep(i, N) {
int X = A[i], Y = B[i];
add(s, T[2000+A[i]][2000+B[i]]);
}
rep(i, N) {
add(s, MOD-nCr[2*A[i]+2*B[i]][2*A[i]]);
}
s = (500000004LL*s)%MOD;
cout << s << "\n";
return 0;
}
| codenet | -1 | 1,440 |
s490076294 | p04051 | 1,507,943,041 | cpp | Accepted | 127 | 64,256 | #include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const int maxn = 200000, mod = 1e9 + 7, maxx = 4001, offset = 2000;
inline int Add(int a) {
if (a >= mod) a -= mod;
return a;
}
inline int Sub(int a) {
if (a < 0) a += mod;
return a;
}
inline int Mul(int a, int b) {
return (long long)a * b % mod;
}
int Pow(int a, int b) {
int c = 1;
for (; b; b >>= 1) {
if (b & 1) c = Mul(a, c);
a = Mul(a, a);
}
return c;
}
int n, a[maxn], b[maxn];
int dp[maxx][maxx];
int fact[8001], ifact[8001];
inline int Choose(int n, int m) {
return Mul(fact[n], Mul(ifact[m], ifact[n - m]));
}
int main(void) {
fact[0] = 1;
for (int i = 1; i <= 8000; ++i) {
fact[i] = Mul(fact[i - 1], i);
}
ifact[8000] = Pow(fact[8000], mod - 2);
for (int i = 8000; i >= 1; --i) {
ifact[i - 1] = Mul(ifact[i], i);
}
scanf("%d", &n);
int ans = 0;
for (int i = 0; i < n; ++i) {
scanf("%d%d", a + i, b + i);
++dp[offset - a[i]][offset - b[i]];
ans = Sub(ans - Choose(a[i] + b[i] << 1, a[i] << 1));
}
for (int i = 0; i < maxx; ++i) {
for (int j = 0; j < maxx; ++j) {
if (i) {
dp[i][j] = Add(dp[i][j] + dp[i - 1][j]);
}
if (j) {
dp[i][j] = Add(dp[i][j] + dp[i][j - 1]);
}
}
}
for (int i = 0; i < n; ++i) {
ans = Add(ans + dp[offset + a[i]][offset + b[i]]);
}
printf("%d\n", Mul(ans, Pow(2, mod - 2)));
return 0;
}
| codenet | -1 | 1,441 |
s466753575 | p04051 | 1,540,417,386 | cpp | Accepted | 105 | 64,640 | #include <cstdio>
#define rg register
using namespace std;
typedef long long ll;
const int maxn=200010,mod=1e9+7,inv2=500000004;
template <typename Tp> inline int getmin(Tp &x,Tp y){return y<x?x=y,1:0;}
template <typename Tp> inline int getmax(Tp &x,Tp y){return y>x?x=y,1:0;}
template <typename Tp> inline void read(Tp &x)
{
x=0;int f=0;char ch=getchar();
while(ch!='-'&&(ch<'0'||ch>'9')) ch=getchar();
if(ch=='-') f=1,ch=getchar();
while(ch>='0'&&ch<='9') x=x*10+ch-'0',ch=getchar();
if(f) x=-x;
}
int n,ans,a[maxn],b[maxn],fac[8010],inv[8010],f[4010][4010];
inline int pls(int x,int y){return x+y>=mod?x+y-mod:x+y;}
inline int dec(int x,int y){return x-y<0?x-y+mod:x-y;}
int power(int x,int y)
{
int res=1;
for(;y;y>>=1,x=(ll)x*x%mod)
if(y&1)
res=(ll)res*x%mod;
return res;
}
inline int c(int n,int m){return m>n?0:(ll)fac[n]*inv[m]%mod*inv[n-m]%mod;}
int main()
{
read(n);fac[0]=1;
for(rg int i=1;i<=n;i++)
{
read(a[i]),read(b[i]);
++f[2000-a[i]][2000-b[i]];
}
for(rg int i=1;i<=8000;i++) fac[i]=(ll)fac[i-1]*i%mod;
inv[8000]=power(fac[8000],mod-2);
for(rg int i=7999;~i;i--) inv[i]=(ll)inv[i+1]*(i+1)%mod;
for(rg int i=0;i<=4000;i++)
for(rg int j=0;j<=4000;j++)
f[i][j]=pls(f[i][j],pls(i?f[i-1][j]:0,j?f[i][j-1]:0));
for(rg int i=1;i<=n;i++)
{
ans=pls(ans,f[2000+a[i]][2000+b[i]]);
ans=dec(ans,c((a[i]+b[i])<<1,a[i]<<1));
}
ans=(ll)ans*inv2%mod;
printf("%d\n",ans);
return 0;
} | codenet | -1 | 1,443 |
s144375941 | p04051 | 1,562,857,118 | cpp | Accepted | 130 | 64,640 | //by OIerC
//Forca Barcelona!
#include<cstdio>
using namespace std;
const int P = 1e9 + 7;
void add(int &a, int b){a += b; a >= P ? a -= P : 0;}
void sub(int &a, int b){a -= b; a < 0 ? a += P : 0;}
inline int read()
{
int x = 0, f = 1; char ch = getchar();
for (; ch < '0' || ch > '9'; ch = getchar()) if (ch == '-') f = -1;
for (; ch >= '0' && ch <= '9'; ch = getchar()) x = (x << 1) + (x << 3) + ch - '0';
return x * f;
}
const int M = 2e3 + 5, N = 2e5 + 5;
int a[N], b[N], dp[M * 2][M * 2];
int fac[M * 4 + 5], ifac[M * 4 + 5];
int ans;
int Pow(int x, int t)
{
int res = 1;
for (; t; t >>= 1, x = 1LL * x * x % P)
if (t & 1) res = 1LL * res * x % P;
return res;
}
int C(int n, int m)
{
if (n < m) return 0;
return 1LL * fac[n] * ifac[n - m] % P * ifac[m] % P;
}
int main()
{
int n = read();
for (int i = 1; i <= n; ++i)
a[i] = read(), b[i] = read();
for (int i = 1; i <= n; ++i) ++dp[M - a[i]][M - b[i]];
for (int i = 1; i < 2 * M; ++i)
for (int j = 1; j < 2 * M; ++j)
add(dp[i][j], (dp[i][j - 1] + dp[i - 1][j]) % P);
for (int i = 1; i <= n; ++i)
add(ans, dp[a[i] + M][b[i] + M]);
fac[0] = 1;
for (int i = 1; i <= 4 * M; ++i) fac[i] = 1LL * fac[i - 1] * i % P;
ifac[4 * M] = Pow(fac[4 * M], P - 2);
for (int i = 4 * M; i; --i) ifac[i - 1] = 1LL * ifac[i] * i % P;
for (int i = 1; i <= n; ++i)
sub(ans, C(2 * a[i] + 2 * b[i], 2 * a[i]));
printf("%d\n", 1LL * ans * ifac[2] % P);
return 0;
}
| codenet | -1 | 1,445 |
s038121802 | p04051 | 1,538,543,967 | cpp | Accepted | 209 | 64,512 | #include<bits/stdc++.h>
#define ED(x) ((int)x.size()-1)
#define _for(i,a,b) for(int i=(a);i<=(b);++i)
#define _rep(i,a,b) for(int i=(a);i>=(b);--i)
#define changxv ios::sync_with_stdio(0);cin.tie(0);
using namespace std;
typedef long long ll;
template<typename T>void dbg(const char*s,T h){cerr<<s<<'='<<h<<'\n';}
template<typename T,typename...A>void dbg(const char*s,T h,A...t){
while(*s!=',')cerr<<*s++;cerr<<'='<<h<<", ";dbg(s+1,t...);
}
#define put(...) dbg(#__VA_ARGS__, __VA_ARGS__)
const int maxn=2003;
const int INF=0x3f3f3f3f;
const int P=2001;
const int mod=1e9+7;
struct node{
int x,y;
}p[200003];
int f[maxn<<1][maxn<<1];
int fac[maxn<<2],invfac[maxn<<2];
int Qpow(int x,int k){
int tmp=1;
for(;k;k>>=1,x=(ll)x*x%mod)if(k&1)tmp=(ll)tmp*x%mod;
return tmp;
}
void Pre(){
const int lim=8002;
fac[0]=invfac[0]=1;
_for(i,1,lim)fac[i]=(ll)fac[i-1]*i%mod;
invfac[lim]=Qpow(fac[lim],mod-2);
_rep(i,lim-1,1)invfac[i]=(ll)invfac[i+1]*(i+1)%mod;
}
int C(int n,int m){
if(n<m)return 0;
return (ll)fac[n]*invfac[m]%mod*invfac[n-m]%mod;
}
int main(){changxv
Pre();
int n;cin>>n;
_for(i,1,n){
int x,y;cin>>x>>y;
p[i]=(node){x,y};
++f[-x+P][-y+P];
}
_for(i,1,2000+P){
_for(j,1,2000+P){
(f[i][j]+=(f[i-1][j]+f[i][j-1])%mod)%=mod;
}
}
int ans=0;
_for(i,1,n){
(ans+=f[P+p[i].x][P+p[i].y])%=mod;
(ans-=C(p[i].x+p[i].y<<1,p[i].x<<1)-mod)%=mod;
}
ans=(ll)ans*Qpow(2,mod-2)%mod;
cout<<ans<<'\n';
return 0; } | codenet | -1 | 1,446 |
s025261894 | p04051 | 1,519,165,184 | cpp | Accepted | 125 | 1,920 | #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
using namespace std;
#define MOD 1000000007
#define f(i,j) f[(i)&1][(j)+4000]
#define rint register int
#define gc() getchar()
inline int read(rint ans = 0, rint sgn = ' ', rint ch = gc())
{
for(; ch < '0' || ch > '9'; sgn = ch, ch = gc());
for(; ch >='0' && ch <='9';(ans*=10)+=ch-'0', ch = gc());
return sgn-'-'?ans:-ans;
}
typedef pair<int,int> pii; pii p[200005]; int f[2][8005], fac[8005], efac[8005], n, X, Y, K, Ans;
inline int exp(int s, int n=MOD-2){int a=1; for(; n; n&1 ? a = 1ll*a*s%MOD : 0, s = 1ll*s*s%MOD, n >>= 1); return a;}
inline int C(int n, int k){return 1ll*fac[n]*efac[k]%MOD*efac[n-k]%MOD;}
int main()
{
n = read(); for(rint i = 1; i <= n; X = max(X,p[i].first=read()), Y = max(Y,p[i].second=read()), i++); K = (X+Y)<<1, sort(p+1,p+n+1);
for(rint i = -X, j, q = n, t = 1; i <= X; i++)
{
for(j = -Y; j <= Y; j++) for(f(i,j) = f(i-1,j)+f(i,j-1), f(i,j)<MOD?:f(i,j)-=MOD; q && p[q]==pii(-i,-j); ++f(i,j)==MOD?f(i,j)=0:0, q--);
for(; t <= n && p[t].first==i; Ans += f(i,p[t].second), Ans<MOD?:Ans-=MOD, t++);
} fac[0] = 1; for(rint i = 1; i <= K; fac[i] = 1ll*i*fac[i-1]%MOD, i++); efac[K] = exp(fac[K]); for(rint i = K; i; efac[i-1] = 1ll*i*efac[i]%MOD, i--);
for(rint i = 1; i <= n; Ans -= C((p[i].first<<1)+(p[i].second<<1),p[i].first<<1), Ans<0?Ans+=MOD:0, i++); printf("%lld\n",500000004ll*Ans%MOD); return 0;
} | codenet | -1 | 1,446 |
s918112264 | p04051 | 1,552,866,830 | cpp | Accepted | 142 | 64,640 | #include <bits/stdc++.h>
using namespace std;
typedef long long LL;
const int bas = 2e3 + 1, mod = 1e9 + 7;
const int Maxn = 2e5 + 5, N = bas * 2 + 5;
int n, ans, a[Maxn], b[Maxn], f[N][N];
int fac[N * 2], inv[N * 2];
inline int add(int &x, int y) {
x += y; if(x >= mod) x -= mod;
}
inline void sub(int &x, int y) {
x -= y; if(x < 0) x += mod;
}
inline int mul(int x, int y) {
return (LL) x * y % mod;
}
inline int Pow(int a, int b = mod - 2) {
int res = 1;
for(; b; b >>= 1, a = mul(a, a))
if(b & 1) res = mul(res, a);
return res;
}
inline int C(int n, int m) {
if(n < m || n < 0 || m < 0) return 0;
return mul(fac[n], mul(inv[m], inv[n - m]));
}
void init(int n = 8e3) {
inv[0] = fac[0] = 1;
for(int i = 1; i <= n; ++i)
fac[i] = mul(fac[i - 1], i);
inv[n] = Pow(fac[n]);
for(int i = n - 1; i; --i)
inv[i] = mul(inv[i + 1], i + 1);
}
int main() {
init();
scanf("%d", &n);
for(int i = 1; i <= n; ++i) {
scanf("%d%d", a + i, b + i);
++ f[bas - a[i]][bas - b[i]];
}
for(register int i = 1; i <= bas * 2; ++i)
for(register int j = 1; j <= bas * 2; ++j) {
add(f[i][j], f[i - 1][j]);
add(f[i][j], f[i][j - 1]);
}
for(int i = 1; i <= n; ++i) {
add(ans, f[bas + a[i]][bas + b[i]]);
sub(ans, C(2 * (a[i] + b[i]), 2 * a[i]));
}
printf("%d\n", mul(ans, Pow(2)));
return 0;
} | codenet | -1 | 1,447 |
s494440773 | p04051 | 1,509,628,464 | cpp | Accepted | 175 | 126,976 | #include <cmath>
#include <cstdio>
#include <climits>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>
//Constant
const int N=200000;
const int A=2000;
const int D=A*2;
const int F=A*4;
const int MOD=1000000007;
//Quick Read
int Read(){
int x=0;
bool neg=false;
char c=getchar();
while(isdigit(c)==false)neg^=c=='-',c=getchar();
while(isdigit(c)==true)x=x*10+c-'0',c=getchar();
return neg==true?-x:x;
}
inline void Read(int &x){x=Read();}
//Math
long long fac[F+1],facinv[F+1];
int Power(long long x,int y){
long long ans=1;
for(int i=y;i>=1;i>>=1){
if(i&1)ans=ans*x%MOD;
x=x*x%MOD;
}
return ans;
}
inline long long Comb(int n,int m){return (long long)fac[n]*facinv[n-m]%MOD*facinv[m]%MOD;}
//Main
int a[N+1],b[N+1];
long long f[D+1][D+1];
int main(){
// freopen("AGC001E.in","r",stdin);
// freopen("AGC001E.out","w",stdout);
int n=Read();
for(int i=1;i<=n;++i)Read(a[i]),Read(b[i]),++f[A-a[i]][A-b[i]];
for(int i=0;i<=D;++i)
for(int j=0;j<=D;++j){
if(i!=0)f[i][j]=(f[i][j]+f[i-1][j])%MOD;
if(j!=0)f[i][j]=(f[i][j]+f[i][j-1])%MOD;
}
long long ans=0;
for(int i=1;i<=n;++i)ans+=f[A+a[i]][A+b[i]];
fac[0]=1;
for(int i=1;i<=F;++i)fac[i]=(fac[i-1]*i)%MOD;
facinv[F]=Power(fac[F],MOD-2);
for(int i=F-1;i>=0;--i)facinv[i]=facinv[i+1]*(i+1)%MOD;
for(int i=1;i<=n;++i)ans=(ans-Comb((a[i]+b[i])*2,b[i]*2))%MOD;
ans=ans*facinv[2]%MOD;
if(ans<0)ans+=MOD;
printf("%lld\n",ans);
return 0;
}
| codenet | -1 | 1,447 |
s158319730 | p04051 | 1,540,506,099 | cpp | Accepted | 189 | 64,640 | #include<bits/stdc++.h>
using namespace std;
const int mod=1e9+7;
#define inv2 500000004
const int N=200010;const int M=8000;
/*inline int ask(int x)
{
int ans=0;
for(;x;x-=x&-x)
ans+=c[x];
return ans;
}*/
inline int read()
{
int x=0,o=1;char ch=getchar();
while(!isdigit(ch)&&ch!='-') ch=getchar();
if(ch=='-') o=-1,ch=getchar();
while(isdigit(ch)) x=x*10+ch-'0',ch=getchar();
return x*o;
}
int fac[M+10],ifac[M+10],m,f[M/2+10][M/2+10],base=M/4+2,n,A[N],B[N];
inline int Pow(int a,int b)
{
int ans=1;
for(;b;b>>=1,a=1ll*a*a%mod)
if(b&1) ans=1ll*ans*a%mod;
return ans;
}
inline int C(int n,int m)
{
return 1ll*fac[n]*ifac[m]%mod*ifac[n-m]%mod;
}
int main()
{
n=read();
fac[0]=1;
for(register int i=1;i<=M;i++)
fac[i]=1ll*fac[i-1]*i%mod;
ifac[M]=Pow(fac[M],mod-2);
for(register int i=M-1;i>=0;i--)
ifac[i]=1ll*ifac[i+1]*(i+1)%mod;
for(register int i=1;i<=n;i++)
{
A[i]=read();
B[i]=read();
f[base-A[i]][base-B[i]]++;
}
for(register int i=1;i<=M/2+2;i++)
for(register int j=1;j<=M/2+2;j++)
f[i][j]=(f[i][j]+(f[i-1][j]+f[i][j-1])%mod)%mod;
long long ans=0;
for(register int i=1;i<=n;i++)
{
ans=(ans+f[A[i]+base][B[i]+base])%mod;
ans=(ans-C(2*A[i]+2*B[i],2*A[i]))%mod;
}
ans=(ans+mod)%mod;
ans=1ll*inv2*ans%mod;
printf("%lld\n",ans);
return 0;
}
| codenet | -1 | 1,450 |
s737890673 | p04051 | 1,533,322,670 | cpp | Accepted | 284 | 129,152 | #include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef long double ld;
typedef pair <ll , int> pll;
typedef vector <ll> vll;
typedef pair <pll,ll> p3l;
#define pb push_back
#define X first
#define Y second
#define mkp make_pair
#define smax(a,b) a=max(a,b)
#define ER(x) cout<<#x<<" "<<x<<"\n";
#define smin(a,b) a=min(a,b)
#define SZ(s) (ll)((s).size())
#define For(i,a,b) for (int i=a;i<b;i++)
#define Ford(i,a,b) for (int i=a;i>=b;i--)
#define RET(x) {cout<<x<<'\n';} //return 0;}
#define RETD(x) {cout << fixed << setprecision(15) << x <<'\n';}
#define IOS ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0)
const ll maxn=2e5+10,M=4e3+10,SQ=360,bghs=1e9+7,inf=1e18+15,LG=22,I=2e3+5;
ll n,dp[M][M],fac[4*M];
pll ab[maxn];
ll pw(ll x,ll n=bghs-2)
{
if (n==0) return 1;
ll res=pw(x,n/2);
res*=res; res%=bghs;
if (n%2) res*=x,res%=bghs;
return res;
}
ll C(ll i,ll j)
{
return (((fac[i]*pw(fac[j]))%bghs)*pw(fac[i-j]))%bghs;
}
int main()
{
IOS; cin>>n;
For(i,0,n) {cin>>ab[i].X>>ab[i].Y;dp[I-ab[i].X][I-ab[i].Y]++;}
For(i,1,M) For(j,1,M) dp[i][j]+=(dp[i-1][j]+dp[i][j-1]),dp[i][j]%=bghs;
ll ans=0;
fac[0]=1;
For(i,1,4*M) fac[i]=(i*fac[i-1])%bghs;
For(i,0,n)
{
ans=(ans+dp[I+ab[i].X][I+ab[i].Y])%bghs;
//ER(dp[I-ab[i].X][I-ab[i].Y]);
ans=(ans-C(2*(ab[i].X+ab[i].Y),2*ab[i].X))%bghs;
}
cout<<(((ans+bghs)%bghs)*(ll)(5e8 + 4))%bghs<<'\n';
}
| codenet | -1 | 1,451 |
s400009682 | p04051 | 1,565,225,906 | cpp | Accepted | 142 | 84,736 | //quming
#include<bits/stdc++.h>
#define R register
#define fp(i,a,b) for(R int i=(a),I=(b)+1;i<I;++i)
#define fd(i,a,b) for(R int i=(a),I=(b)-1;i>I;--i)
#define go(u) for(int i=head[u],v=e[i].v;i;i=e[i].nx,v=e[i].v)
template<class T>inline bool cmin(T&a,const T&b){return a>b?a=b,1:0;}
template<class T>inline bool cmax(T&a,const T&b){return a<b?a=b,1:0;}
using namespace std;
const int P=1e9+7;
inline void upd(R int &x,R int y){(x+=y)>=P?x-=P:0;}
inline int add(R int x,R int y){return x+y>=P?x+y-P:x+y;}
inline int dec(R int x,R int y){return x-y<0?x-y+P:x-y;}
inline int mul(R int x,R int y){return 1ll*x*y-1ll*x*y/P*P;}
int ksm(R int x,R int y){
R int res=1;
for(;y;y>>=1,x=mul(x,x))(y&1)?res=mul(res,x):0;
return res;
}
const int N=2e5+5,M=5005,S=2005;
int a[N],b[N],fac[N],ifac[N],f[M][M],xmx,ymx,n,res;
inline int C(R int n,R int m){return m>n?0:1ll*fac[n]*ifac[m]%P*ifac[n-m]%P;}
void init(int n){
fac[0]=ifac[0]=1;
fp(i,1,n)fac[i]=mul(fac[i-1],i);
ifac[n]=ksm(fac[n],P-2);fd(i,n-1,1)ifac[i]=mul(ifac[i+1],i+1);
}
int main(){
// freopen("testdata.in","r",stdin);
scanf("%d",&n);
fp(i,1,n)scanf("%d%d",&a[i],&b[i]),cmax(xmx,a[i]),cmax(ymx,b[i]);
init((xmx+ymx)<<1);
fp(i,1,n)++f[S-a[i]][S-b[i]];
fp(i,S-xmx,S+xmx)fp(j,S-ymx,S+ymx)if(f[i][j])upd(f[i+1][j],f[i][j]),upd(f[i][j+1],f[i][j]);
fp(i,1,n)upd(res,f[S+a[i]][S+b[i]]);
fp(i,1,n)res=dec(res,C((a[i]+b[i])<<1,a[i]<<1));
printf("%d\n",mul(res,(P+1)>>1));
return 0;
} | codenet | -1 | 1,452 |
s646111277 | p04051 | 1,528,141,568 | cpp | Accepted | 209 | 189,952 | #include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define sqr(x) ((x)*(x))
#define mp make_pair
#define uint unsigned
#define PI pair<int,int>
inline char gc(){
static char buf[100000],*p1=buf,*p2=buf;
return p1==p2&&(p2=(p1=buf)+fread(buf,1,100000,stdin),p1==p2)?EOF:*p1++;
}
#define gc getchar
inline int read(){
int x = 0; char ch = gc(); bool positive = 1;
for (; !isdigit(ch); ch = gc()) if (ch == '-') positive = 0;
for (; isdigit(ch); ch = gc()) x = x * 10 + ch - '0';
return positive ? x : -x;
}
inline void write(int a){
if(a<0){
a=-a; putchar('-');
}
if(a>=10)write(a/10);
putchar('0'+a%10);
}
inline void writeln(int a){
if(a<0){
a=-a; putchar('-');
}
write(a); puts("");
}
inline int rnd(int x){
return rand()%x;
}
inline ull rnd(){
return ((ull)rand()<<30^rand())<<4|rand()%4;
}
const int N=2005,M=200005,mod=1000000007;
int n,dp[N<<1][N<<1],c[N<<2][N<<1],a[M],b[M],ans;
int main(){
n=read();
for(int i=1;i<=n;i++){
a[i]=read(); b[i]=read();
dp[-a[i]+N][-b[i]+N]++;
}
for(int i=1;i<2*N;i++){
for(int j=1;j<2*N;j++){
dp[i][j]=(dp[i-1][j]+dp[i][j-1]+dp[i][j])%mod;
}
}
for(int i=0;i<4*N;i++){
c[i][0]=1;
for(int j=1;j<2*N&&j<=i;j++)c[i][j]=(c[i-1][j-1]+c[i-1][j])%mod;
}
for(int i=1;i<=n;i++){ans=(ans+dp[a[i]+N][b[i]+N])%mod; ans=(ans-c[a[i]*2+b[i]*2][a[i]*2])%mod;}
cout<<((ll)ans*(mod+1)/2%mod+mod)%mod<<endl;
}
/*
10*3*4
*/ | codenet | -1 | 1,454 |
s819603694 | p04051 | 1,518,980,932 | cpp | Accepted | 229 | 96,256 | #include<cstdio>
#include<cstring>
#include<iostream>
#include<stdlib.h>
#include<ctime>
#include<string>
#include<cmath>
#include<algorithm>
#include<vector>
#include<set>
#include<map>
#include<queue>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define LL long long
#define FOR(i,a,b) for (int i=a;i<=b;i++)
#define FORD(i,a,b) for (int i=a;i>=b;i--)
using namespace std;
typedef pair<int,int> pa;
void getint(int &v){
char ch,fu=0;
for(ch='*'; (ch<'0'||ch>'9')&&ch!='-'; ch=getchar());
if(ch=='-') fu=1, ch=getchar();
for(v=0; ch>='0'&&ch<='9'; ch=getchar()) v=v*10+ch-'0';
if(fu) v=-v;
}
const int MO=1e9+7;
LL ans,fac[8010],inv[8010];
int n,v[4010][4010],tag[4010][4010],a[200010],b[200010];
LL pw(LL x,LL y){
LL t=1;
for (;y;y>>=1){
if (y&1) t=t*x%MO;
x=x*x%MO;
}
return t;
}
LL C(int x,int y){
return fac[x]*inv[y]%MO*inv[x-y]%MO;
}
int main(){
scanf("%d",&n);
FOR(i,1,n){
scanf("%d%d",&a[i],&b[i]);
v[2000-a[i]][2000-b[i]]++;
tag[2000+a[i]][2000+b[i]]++;
}
FOR(i,0,4000)
FOR(j,0,4000){
(v[i+1][j]+=v[i][j])%=MO;
(v[i][j+1]+=v[i][j])%=MO;
}
FOR(i,0,4000)
FOR(j,0,4000)
(ans+=1ll*v[i][j]*tag[i][j])%=MO;
fac[0]=1;
FOR(i,1,8000) fac[i]=fac[i-1]*i%MO;
inv[8000]=pw(fac[8000],MO-2);
FORD(i,7999,0) inv[i]=inv[i+1]*(i+1)%MO;
FOR(i,1,n)
(ans-=C(a[i]+a[i]+b[i]+b[i],a[i]+a[i]))%=MO;
ans=ans*pw(2,MO-2)%MO;
ans=(ans%MO+MO)%MO;
cout<<ans<<endl;
return 0;
}
| codenet | -1 | 1,454 |
s822443266 | p04051 | 1,552,888,091 | cpp | Accepted | 191 | 91,904 | #include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<queue>
#include<stack>
#include<map>
#include<bitset>
#include<vector>
using namespace std;
#define i32 int
#define i64 long long
#define db double
#define rep(i,s,n) for(i32 i=s;i<=n;i++)
#define rep_(i,n,s) for(i32 i=n;i>=s;i--)
i32 RI(){
char ch=getchar();i32 sum=0,f=1;
while(!isdigit(ch)){
if(ch=='-')f=-1;
ch=getchar();
}
while(isdigit(ch))sum=sum*10+ch-'0',ch=getchar();
return f*sum;
}
i64 RL(){
char ch=getchar();i64 sum=0;
while(!isdigit(ch))ch=getchar();
while(isdigit(ch))sum=sum*10+ch-'0',ch=getchar();
return sum;
}
const i32 N=5005;
const i32 mod=1e9+7;
i32 n,ans;
i32 F[N][N],A[300000],B[300000],jc[N<<2];
i32 ksm(i32 x,i32 y){
i32 s=1;
while(y){
if(y&1)s=1LL*s*x%mod;
y>>=1;
x=1LL*x*x%mod;
}
return s;
}
i32 C(i32 x,i32 y){return 1LL*jc[x]*ksm(1LL*jc[x-y]*jc[y]%mod,mod-2)%mod;}
i32 get(i32 x,i32 y){return C(x+y,x);}
i32 main(){
n=RI();
rep(i,1,n){A[i]=RI();B[i]=RI();F[-A[i]+2001][-B[i]+2001]++;}
jc[0]=1;rep(i,1,10000)jc[i]=1LL*jc[i-1]*i%mod;
rep(i,1,4500){
rep(j,1,4500){
F[i][j]=(F[i][j]+F[i-1][j]+F[i][j-1])%mod;
}
}
rep(i,1,n){
ans=(ans+F[A[i]+2001][B[i]+2001])%mod;
ans=(ans-get(A[i]<<1,B[i]<<1)+mod)%mod;
}
ans=1LL*ans*ksm(2,mod-2)%mod;
printf("%d",ans);
} | codenet | -1 | 1,456 |
s251566453 | p04051 | 1,567,484,270 | cpp | Accepted | 190 | 64,640 | #include <iostream>
#include <cstdio>
#include <cstring>
#define MOD 1000000007
using namespace std;
typedef long long LL;
const int MAXN = 2e05 + 10;
const int MAXM = 4000 + 10;
const int q = 2002;
LL fact[MAXM << 1]= {0}, invfact[MAXM << 1]= {0};
inline LL C (int n, int m) {
return fact[n] * invfact[m] % MOD * invfact[n - m] % MOD;
}
int f[MAXM][MAXM]= {0};
int N;
int x[MAXN], y[MAXN];
int getnum () {
int num = 0;
char ch = getchar ();
while (! isdigit (ch))
ch = getchar ();
while (isdigit (ch))
num = (num << 3) + (num << 1) + ch - '0', ch = getchar ();
return num;
}
int main () {
N = getnum ();
for (int i = 1; i <= N; i ++) {
x[i] = getnum (), y[i] = getnum ();
f[- x[i] + q][- y[i] + q] ++;
}
for (int i = 1; i <= (q << 1); i ++)
for (int j = 1; j <= (q << 1); j ++)
f[i][j] = (f[i][j] + (f[i - 1][j] + f[i][j - 1]) % MOD) % MOD;
LL ans = 0;
for (int i = 1; i <= N; i ++)
ans = (ans + f[x[i] + q][y[i] + q]) % MOD;
fact[0] = invfact[0] = invfact[1] = 1;
for (int i = 1; i <= (q << 2); i ++) {
fact[i] = fact[i - 1] * i % MOD;
if (i > 1) invfact[i] = (MOD - MOD / i) * invfact[MOD % i] % MOD;
}
for (int i = 1; i <= (q << 2); i ++)
invfact[i] = invfact[i] * invfact[i - 1] % MOD;
for (int i = 1; i <= N; i ++)
ans = (ans - C ((x[i] + y[i]) << 1, x[i] << 1) + MOD) % MOD;
ans = ans * invfact[2] % MOD;
cout << ans << endl;
return 0;
}
/*
3
1 1
1 1
2 1
*/
/*
3
1999 1999
1999 1999
2000 1999
*/ | codenet | -1 | 1,460 |
s864300628 | p04051 | 1,485,315,221 | cpp | Accepted | 467 | 128,896 | #include<bits/stdc++.h>
using namespace std;
#define int long long
typedef vector<int>vint;
typedef pair<int,int>pint;
typedef vector<pint>vpint;
#define rep(i,n) for(int i=0;i<(n);i++)
#define reps(i,f,n) for(int i=(f);i<(n);i++)
#define all(v) (v).begin(),(v).end()
#define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();it++)
#define pb push_back
#define fi first
#define se second
template<typename A,typename B>inline void chmin(A &a,B b){if(a>b)a=b;}
template<typename A,typename B>inline void chmax(A &a,B b){if(a<b)a=b;}
const int mod=1000000007;
int dp[4010][4010];
int N;
int A[222222],B[222222];
inline void add(int &a,int b){a+=b;if(a>=mod)a-=mod;}
int mpow(int n,int m){
int ret=1;
while(m){
if(m&1)ret=ret*n%mod;
n=n*n%mod;
m>>=1;
}
return ret;
}
int fact[8888],inv[8888];
signed main(){
cin>>N;
rep(i,N)cin>>A[i]>>B[i];
rep(i,N)dp[2000-A[i]][2000-B[i]]++;
for(int i=0;i<=4000;i++){
for(int j=0;j<=4000;j++){
add(dp[i+1][j],dp[i][j]);
add(dp[i][j+1],dp[i][j]);
}
}
fact[0]=1;
for(int i=1;i<=8000;i++)fact[i]=fact[i-1]*i%mod;
inv[8000]=mpow(fact[8000],mod-2);
for(int i=7999;i>=0;i--)inv[i]=inv[i+1]*(i+1)%mod;
int ans=0;
rep(i,N)add(ans,dp[2000+A[i]][2000+B[i]]);
rep(i,N)ans=(ans-fact[(A[i]+B[i])*2]*inv[A[i]*2]%mod*inv[B[i]*2]%mod+mod)%mod;
cout<<ans*inv[2]%mod<<endl;
return 0;
}
| codenet | -1 | 1,460 |
s091920638 | p04051 | 1,562,969,522 | cpp | Accepted | 199 | 82,816 | /*
* Author : YangDavid
* Created Time : 2019年07月12日 星期五 16时59分54秒
*/
#include<bits/stdc++.h>
#define rep(i, n) for(int i = 1; i <= n; ++i)
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
const int maxn = 222222, MOD = 1000000007, inv2 = (MOD + 1) / 2, D = 2003;
int muln(int x, int y) { return 1LL * x * y % MOD; }
int mo(int x) { if(x >= MOD) x -= MOD; if(x < 0) x += MOD; return x; }
int qpow(int x, int y) {
int ret = 1;
for(; y; y >>= 1, x = muln(x, x))
if(y & 1) ret = muln(ret, x);
return ret;
}
int inv(int x) { return qpow(x, MOD - 2); }
int n, a[maxn], b[maxn], dp[4030][4030], fac[maxn], ifac[maxn], p[2010][2010], ans;
int f(int x, int y) { return muln(fac[x + y], muln(ifac[x], ifac[y])); }
int main() {
scanf("%d", &n);
rep(i, n) {
scanf("%d%d", &a[i], &b[i]);
dp[-a[i] + D][-b[i] + D]++;
p[a[i]][b[i]]++;
}
fac[0] = ifac[0] = 1;
for(int i = 1; i <= 200000; ++i) {
fac[i] = muln(fac[i - 1], i);
ifac[i] = inv(fac[i]);
}
for(int i = -2000; i <= 2000; ++i) {
for(int j = -2000; j <= 2000; ++j) {
dp[i+D][j+D] = mo(dp[i+D][j+D] + dp[i - 1+D][j+D] + dp[i+D][j - 1+D]);
if(i >= 0 && j >= 0) ans = mo(ans + muln(dp[i+D][j+D], p[i][j]));
}
}
for(int i = 1; i <= n ;++i)
ans = mo(ans - f(2 * a[i], 2 * b[i]));
ans = muln(ans, inv2);
printf("%d\n", ans);
return 0;
}
| codenet | -1 | 1,464 |
s091920638 | p04051 | 1,562,969,522 | cpp | Accepted | 199 | 82,816 | /*
* Author : YangDavid
* Created Time : 2019年07月12日 星期五 16时59分54秒
*/
#include<bits/stdc++.h>
#define rep(i, n) for(int i = 1; i <= n; ++i)
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
const int maxn = 222222, MOD = 1000000007, inv2 = (MOD + 1) / 2, D = 2003;
int muln(int x, int y) { return 1LL * x * y % MOD; }
int mo(int x) { if(x >= MOD) x -= MOD; if(x < 0) x += MOD; return x; }
int qpow(int x, int y) {
int ret = 1;
for(; y; y >>= 1, x = muln(x, x))
if(y & 1) ret = muln(ret, x);
return ret;
}
int inv(int x) { return qpow(x, MOD - 2); }
int n, a[maxn], b[maxn], dp[4030][4030], fac[maxn], ifac[maxn], p[2010][2010], ans;
int f(int x, int y) { return muln(fac[x + y], muln(ifac[x], ifac[y])); }
int main() {
scanf("%d", &n);
rep(i, n) {
scanf("%d%d", &a[i], &b[i]);
dp[-a[i] + D][-b[i] + D]++;
p[a[i]][b[i]]++;
}
fac[0] = ifac[0] = 1;
for(int i = 1; i <= 200000; ++i) {
fac[i] = muln(fac[i - 1], i);
ifac[i] = inv(fac[i]);
}
for(int i = -2000; i <= 2000; ++i) {
for(int j = -2000; j <= 2000; ++j) {
dp[i+D][j+D] = mo(dp[i+D][j+D] + dp[i - 1+D][j+D] + dp[i+D][j - 1+D]);
if(i >= 0 && j >= 0) ans = mo(ans + muln(dp[i+D][j+D], p[i][j]));
}
}
for(int i = 1; i <= n ;++i)
ans = mo(ans - f(2 * a[i], 2 * b[i]));
ans = muln(ans, inv2);
printf("%d\n", ans);
return 0;
}
| codenet | -1 | 1,464 |
s050960439 | p04051 | 1,505,271,294 | cpp | Accepted | 104 | 98,304 | #include<iostream>
#include<cstring>
#include<cstdio>
#include<algorithm>
#include<cmath>
#include<set>
#include<bitset>
#include<map>
#define fo(i,a,b) for(int i=a;i<=b;i++)
#define fd(i,a,b) for(int i=a;i>=b;i--)
using namespace std;
typedef long long LL;
typedef double db;
int get(){
char ch;
while(ch=getchar(),(ch<'0'||ch>'9')&&ch!='-');
if (ch=='-'){
int s=0;
while(ch=getchar(),ch>='0'&&ch<='9')s=s*10+ch-'0';
return -s;
}
int s=ch-'0';
while(ch=getchar(),ch>='0'&&ch<='9')s=s*10+ch-'0';
return s;
}
const int mo = 1e+9+7;
const int N = 2e+3;
int f[N*2+3][N*2+3];
LL ny[N*4+3],js[N*4+3];
int n;
LL ans;
int ad[N*2+3][N*2+3];
struct point{
int x,y;
}a[200003];
LL quickmi(LL x,LL tim){
LL ans=1;
x%=mo;
for(;tim;tim/=2,x=x*x%mo)if (tim&1)ans=ans*x%mo;
return ans;
}
inline int add(int x,int y){
return x+y>=mo?x+y-mo:x+y;
}
LL calc(int x,int y){
return js[x*2+y*2]*ny[x*2]%mo*ny[y*2]%mo;
}
int main(){
n=get();
fo(i,1,n){
int x=get(),y=get();
a[i].x=x;a[i].y=y;
ad[N-a[i].x][N-a[i].y]++;
}
js[0]=1;
fo(i,1,8000)js[i]=js[i-1]*i%mo;
ny[8000]=quickmi(js[8000],mo-2);
fd(i,7999,0)ny[i]=ny[i+1]*(i+1)%mo;
fo(i,0,4000)
fo(j,0,4000){
if (i>0)f[i][j]=add(f[i][j],f[i-1][j]);
if (j>0)f[i][j]=add(f[i][j],f[i][j-1]);
f[i][j]=add(f[i][j],ad[i][j]);
}
ans=0;
fo(i,1,n)ans=add(ans,f[a[i].x+N][a[i].y+N]);
fo(i,1,n)ans=(ans+mo-calc(a[i].x,a[i].y))%mo;
ans=ans*((mo+1)/2)%mo;
printf("%lld\n",ans);
return 0;
} | codenet | -1 | 1,464 |
s063498182 | p04051 | 1,507,665,194 | cpp | Accepted | 107 | 78,848 | #include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define SZ(x) ((x).size())
#define All(x) (x).begin(),(x).end()
#define rep(i,a,b) for(int (i)=(a);(i)<=(b);(i)++)
#define rep2(i,a,b) for(int (i)=(a);(i)<(b);(i)++)
#define per(i,a,b) for(int (i)=(a);(i)>=(b);(i)--)
#define Rep(p,x) for(int (p)=head[(x)];(p);(p)=nxt[(p)])
template<class T>void read(T&num){
num=0;T f=1;char ch=getchar();
while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
while(ch>='0'&&ch<='9')num=num*10+ch-'0',ch=getchar();
num*=f;
}
const int maxn=2e3+5,mod=1e9+7;
int n,ans;
int fac[maxn<<2],ifac[maxn<<2];
int cnt[maxn][maxn],f[maxn<<1][maxn<<1];
int add(int x,int y){return x+y>=mod?x+y-mod:x+y;}
int sub(int x,int y){return x-y<0?x-y+mod:x-y;}
int power(int x,int k,int p){int res=1;for(;k;k>>=1,x=1ll*x*x%p)if(k&1)res=1ll*res*x%p;return res;}
void upd(int &x,int y){x=add(x,y);}
int C(int x,int y){
return 1ll*fac[x]*ifac[y]%mod*ifac[x-y]%mod;
}
int main(){
fac[0]=1;rep(i,1,8e3)fac[i]=1ll*fac[i-1]*i%mod;
rep(i,0,8e3)ifac[i]=power(fac[i],mod-2,mod);
read(n);
rep(i,1,n){
int x,y;read(x);read(y);
ans=sub(ans,C(x+x+y+y,x+x));
cnt[x][y]++;
}
rep(i,-2000,2000)rep(j,-2000,2000){
if(i<0&&j<0)upd(f[i+2001][j+2001],cnt[-i][-j]);
upd(f[i+2001][j+2001],f[i-1+2001][j+2001]);
upd(f[i+2001][j+2001],f[i+2001][j-1+2001]);
if(i>0&&j>0)upd(ans,1ll*f[i+2001][j+2001]*cnt[i][j]%mod);
}
ans=1ll*ans*power(2,mod-2,mod)%mod;
printf("%d\n",ans);
return 0;
} | codenet | -1 | 1,465 |
s277528942 | p04051 | 1,545,070,880 | cpp | Accepted | 147 | 127,872 | #include <cstdio>
typedef long long LL;
const int MX = 2e3 + 5, N = 2e5 + 5, MOD = 1e9 + 7;
int a[N], b[N], n;
LL f[(MX<<1) + 5][(MX<<1) + 5];
LL jc[(MX<<2) + 5], inv[(MX<<2) + 5], invjc[(MX<<2) + 5];
LL ans;
inline int read() {
int x = 0, f = 1;
char ch = getchar();
while (ch < '0' || ch > '9'){if (ch == '-')f = -1; ch = getchar();}
while (ch >= '0' && ch <= '9'){x = x * 10 + ch - '0'; ch = getchar();}
return x * f;
}
inline void add(LL &a, LL b) {
a += b;
if (a >= MOD)a -= MOD;
}
inline LL calc(int a, int b) {
return (LL)jc[a] * invjc[b] % MOD * invjc[a - b] % MOD;
}
int main() {
n = read();
for (int i = 1; i <= n; ++i) {
a[i] = read();
b[i] = read();
f[MX - a[i]][MX - b[i]]++;
}
for (int i = 1; i <= (MX << 1); ++i) {
for (int j = 1; j <= (MX << 1); ++j) {
add(f[i][j], f[i - 1][j]);
add(f[i][j], f[i][j - 1]);
}
}
invjc[0] = invjc[1] = inv[0] = inv [1] = jc [0] = jc [1] = 1;
for (int i = 2; i <= (MX << 2); ++i)jc[i] = (LL)jc[i - 1] * i % MOD;
for (int i = 2; i <= (MX << 2); ++i)inv[i] = (LL)(MOD - MOD / i) * inv[MOD % i] % MOD;
for (int i = 2; i <= (MX << 2); ++i)invjc[i] = (LL)invjc[i - 1] * inv[i] % MOD;
for (int i = 1; i <= n; ++i)add(ans, f[a[i] + MX][b[i] + MX]);
for (int i = 1; i <= n; ++i)add(ans, MOD - calc(2 * (a[i] + b[i]), 2 * a[i]));
printf("%lld\n", ans * inv[2] % MOD);
return 0;
}
| codenet | -1 | 1,466 |
s676649719 | p04051 | 1,533,614,626 | cpp | Accepted | 170 | 127,232 | #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pp;
typedef pair<ll,ll> pll;
void read(int& x){ scanf("%d",&x); }
void read(ll& x){ scanf("%lld",&x); }
void read(pp& x){ scanf("%d%d",&x.first, &x.second); }
void read(pll& x){ scanf("%lld%lld",&x.first, &x.second); }
template<typename T,typename... Args>
void read(T& a,Args&... b){ read(a); read(b...); }
#define all(x) (x).begin(),(x).end()
#define pb push_back
#define eb emplace_back
#define x first
#define y second
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define sz(x) (int)(x).size()
int n;
const ll mod = int(1e9) + 7;
ll dp[4010][4010];
pp d[200010];
ll fact[8010];
ll frev[8010];
ll ppow(ll b, ll e){
ll ret = 1;
while(e){
if(e&1) (ret*=b)%=mod;
(b*=b)%=mod; e>>=1;
}
return ret;
}
int main()
{
read(n);
rrep(i, n) read(d[i]), ++dp[2000-d[i].x][2000-d[i].y];
rep(i, 4001) rep(j, 4001){
if(i) (dp[i][j] += dp[i-1][j]) %= mod;
if(j) (dp[i][j] += dp[i][j-1]) %= mod;
}
fact[0]=1;
rrep(i, 8000) fact[i]=fact[i-1]*i%mod;
frev[8000]=ppow(fact[8000], mod-2);
for(int i=7999; 0<=i; --i) frev[i]=frev[i+1]*(i+1)%mod;
ll ans = 0;
rrep(i, n){
int x, y; tie(x, y) = d[i];
(ans += dp[x+2000][y+2000]) %= mod;
}
rrep(i, n){
int x, y; tie(x, y) = d[i];
(ans += mod - fact[x+y<<1]*frev[x<<1]%mod*frev[y<<1]%mod) %= mod;
}
(ans *= (mod+1)/2) %= mod;
printf("%lld\n", ans);
return 0;
}
| codenet | -1 | 1,466 |
s154455618 | p04051 | 1,578,882,672 | cpp | Accepted | 135 | 73,856 | #include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdio>
const int mod = 1000000007;
const int N = 4005;
const int M = 8000;
using namespace std;
int f[N + 505][N + 505], a[200005], b[200005], fac[M << 1], inv[M << 1], base, ans, n;
template < typename T >
inline T read()
{
T x = 0, w = 1; char c = getchar();
while(c < '0' || c > '9') { if(c == '-') w = -1; c = getchar(); }
while(c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();
return x * w;
}
int fpow(int x, int y)
{
int res = 1;
while(y)
{
if(y & 1)
res = 1ll * res * x % mod;
x = 1ll * x * x % mod;
y >>= 1;
}
return res;
}
int C(int n, int m) { return 1ll * fac[n] * inv[m] % mod * inv[n - m] % mod; }
int main()
{
n = read <int> (), base = 2002;
for(int i = (fac[0] = 1); i <= M; i++)
fac[i] = 1ll * fac[i - 1] * i % mod;
inv[M] = fpow(fac[M], mod - 2);
for(int i = M - 1; i >= 0; i--)
inv[i] = 1ll * inv[i + 1] * (i + 1) % mod;
for(int i = 1; i <= n; i++)
{
a[i] = read <int> (), b[i] = read <int> ();
f[base - a[i]][base - b[i]]++;
}
for(int i = 1; i <= base + 2000; i++)
for(int j = 1; j <= base + 2000; j++)
f[i][j] = (1ll * f[i][j] + f[i - 1][j] + f[i][j - 1]) % mod;
for(int i = 1; i <= n; i++)
{
ans = (1ll * ans + f[base + a[i]][base + b[i]]) % mod;
ans = (1ll * ans - C(2 * a[i] + 2 * b[i], 2 * a[i])) % mod;
}
ans = (ans + mod) % mod;
ans = 1ll * ans * 500000004 % mod;
printf("%d\n", ans);
return 0;
}
| codenet | -1 | 1,468 |
s610861816 | p04051 | 1,535,840,165 | cpp | Accepted | 185 | 66,176 | #include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 5;
const int M = 2e3 + 5;
const int mod = 1e9 + 7;
int n, a[N], b[N], fact[N], inv_fact[N], dp[M * 2][M * 2], ans = 0;
int binPow (int x, int y) {
int ans = 1;
while (y > 0) {
if (y & 1) ans = (1LL * ans * x) % mod;
x = (1LL * x * x) % mod;
y >>= 1;
}
return ans;
}
void prep(){
fact[0] = inv_fact[0] = 1;
for (int i = 1; i < N; i++) {
fact[i] = (1LL * i * fact[i - 1]) % mod;
inv_fact[i] = binPow(fact[i], mod - 2);
}
}
void add (int &x, int y) {
x = (x + y) % mod;
}
int C (int n, int k) {
int res = 1; res = 1LL * res * fact[n] % mod;
res = 1LL * res * inv_fact[k] % mod;
res = 1LL * res * inv_fact[n - k] % mod;
return res;
}
int main(){
scanf("%d", &n);
memset(dp, 0, sizeof(dp));
for (int i = 1; i <= n; i++) {
scanf("%d %d", &a[i], &b[i]);
dp[-a[i] + M - 5][-b[i] + M - 5]++;
}
prep();
for (int i = 0; i < M * 2; i++) {
for (int j = 0; j < M * 2; j++) {
if (i) add(dp[i][j], dp[i - 1][j]);
if (j) add(dp[i][j], dp[i][j - 1]);
}
}
for (int i = 1; i <= n; i++) add(ans, dp[a[i] + M - 5][b[i] + M - 5]);
for (int i = 1; i <= n; i++) ans = (ans - C(a[i] * 2 + b[i] * 2, a[i] * 2)) % mod;
ans = (1LL * ans * binPow(2, mod - 2)) % mod;
if (ans < 0) ans += mod;
printf("%d", ans);
return 0;
}
| codenet | -1 | 1,468 |
s213938211 | p04051 | 1,468,728,008 | cpp | Accepted | 582 | 67,712 | #include <iostream>
#include <cstdio>
#include <cstring>
#include <cassert>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <algorithm>
using namespace std;
typedef long long ll;
const ll MOD = 1e9 + 7;
/*
f(x, y) = C(x + y, y)
(0, 0) -> (x, y) = f(x - 0, y - 0)
(a, b) -> (c, d) = f(c - a, d - b) (a <= c && b <= d)
f(A[i] + A[j], B[i] + B[j]) がほしい
(-A[j], -B[j]) -> (A[i], B[i]) = f(A[i] + A[j], B[i] + B[j])
*/
ll f[9000], finv[9000];
ll C(int n, int k){
ll res = f[n];
res = (res * finv[k]) % MOD;
res = (res * finv[n - k]) % MOD;
return res;
}
int ways[4100][4100];
void add(int &x, int y){
x = (x + y) % MOD;
}
ll mod_pow(ll x, ll e){
ll v = 1;
for(;e;e>>=1){
if(e & 1)v = (v * x) % MOD;
x = (x * x) % MOD;
}
return v;
}
int main(){
f[0] = 1;
for(int i=1;i<9000;i++)f[i] = f[i-1] * i % MOD;
finv[8999] = mod_pow(f[8999], MOD - 2);
for(int i=8998;i>=0;i--)finv[i] = finv[i + 1] * (i + 1) % MOD;
int N;
cin >> N;
vector<int> A(N), B(N);
for(int i=0;i<N;i++){
cin >> A[i] >> B[i];
}
for(int i=0;i<N;i++){
ways[2000 - A[i]][2000 - B[i]] += 1;
}
for(int i=0;i<4100;i++)for(int j=0;j<4100;j++){
if(i > 0) add(ways[i][j], ways[i-1][j]);
if(j > 0) add(ways[i][j], ways[i][j-1]);
}
ll res = 0;
for(int i=0;i<N;i++){
res += ways[2000 + A[i]][2000 + B[i]];
res += MOD - C(2 * A[i] + 2 * B[i], 2 * A[i]);
res %= MOD;
}
res = (res * mod_pow(2, MOD - 2)) % MOD;
cout << res << endl;
return 0;
}
| codenet | -1 | 1,475 |
s275878531 | p04051 | 1,490,027,677 | cpp | Accepted | 233 | 128,768 | //satyaki3794
#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define MOD (1000000007LL)
#define LEFT(n) (2*(n))
#define RIGHT(n) (2*(n)+1)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> ii;
ll pwr(ll base, ll p, ll mod = MOD){
ll ans = 1;while(p){if(p&1)ans=(ans*base)%mod;base=(base*base)%mod;p/=2;}return ans;
}
ll gcd(ll a, ll b){
if(b == 0) return a;
return gcd(b, a%b);
}
const int BASE = 2001;
int n;
ll DP[2*BASE+5][2*BASE+5], A[200005], B[200005], fac[8002];
ll C(int n, int r){
ll ans = fac[n];
ans = (ans * pwr(fac[r], MOD-2)) % MOD;
ans = (ans * pwr(fac[n-r], MOD-2)) % MOD;
return ans;
}
int main(){
// ios_base::sync_with_stdio(0);
// cin.tie(0);
fac[0] = 1;
for(int i=1;i<=8000;i++)
fac[i] = (i * fac[i-1]) % MOD;
scanf("%d", &n);
for(int i=1;i<=n;i++){
scanf("%lld%lld", &A[i], &B[i]);
DP[BASE-A[i]][BASE-B[i]]++;
}
for(int i=-2000;i<=2000;i++)
for(int j=-2000;j<=2000;j++){
DP[BASE+i][BASE+j] = (DP[BASE+i][BASE+j] + DP[BASE+i-1][BASE+j] + DP[BASE+i][BASE+j-1]) % MOD;
}
ll ans = 0;
for(int i=1;i<=n;i++){
ans = (ans + DP[BASE+A[i]][BASE+B[i]]) % MOD;
ans = (ans - C(2*A[i]+2*B[i], 2*A[i])) % MOD;
}
ans = (ans * pwr(2, MOD-2)) % MOD;
ans += MOD;
ans %= MOD;
printf("%lld\n", ans);
return 0;
}
| codenet | -1 | 1,476 |
s275878531 | p04051 | 1,490,027,677 | cpp | Accepted | 233 | 128,768 | //satyaki3794
#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define MOD (1000000007LL)
#define LEFT(n) (2*(n))
#define RIGHT(n) (2*(n)+1)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> ii;
ll pwr(ll base, ll p, ll mod = MOD){
ll ans = 1;while(p){if(p&1)ans=(ans*base)%mod;base=(base*base)%mod;p/=2;}return ans;
}
ll gcd(ll a, ll b){
if(b == 0) return a;
return gcd(b, a%b);
}
const int BASE = 2001;
int n;
ll DP[2*BASE+5][2*BASE+5], A[200005], B[200005], fac[8002];
ll C(int n, int r){
ll ans = fac[n];
ans = (ans * pwr(fac[r], MOD-2)) % MOD;
ans = (ans * pwr(fac[n-r], MOD-2)) % MOD;
return ans;
}
int main(){
// ios_base::sync_with_stdio(0);
// cin.tie(0);
fac[0] = 1;
for(int i=1;i<=8000;i++)
fac[i] = (i * fac[i-1]) % MOD;
scanf("%d", &n);
for(int i=1;i<=n;i++){
scanf("%lld%lld", &A[i], &B[i]);
DP[BASE-A[i]][BASE-B[i]]++;
}
for(int i=-2000;i<=2000;i++)
for(int j=-2000;j<=2000;j++){
DP[BASE+i][BASE+j] = (DP[BASE+i][BASE+j] + DP[BASE+i-1][BASE+j] + DP[BASE+i][BASE+j-1]) % MOD;
}
ll ans = 0;
for(int i=1;i<=n;i++){
ans = (ans + DP[BASE+A[i]][BASE+B[i]]) % MOD;
ans = (ans - C(2*A[i]+2*B[i], 2*A[i])) % MOD;
}
ans = (ans * pwr(2, MOD-2)) % MOD;
ans += MOD;
ans %= MOD;
printf("%lld\n", ans);
return 0;
}
| codenet | -1 | 1,476 |
s178393511 | p04051 | 1,495,724,313 | cpp | Accepted | 158 | 63,104 | #include <cstring>
#include <algorithm>
#include <cstdio>
using namespace std;
typedef long long ll;
const int MAXN = 4010;
const int ZERO = 2005;
const int MOD = 1e9+7;
int a[MAXN][MAXN] = {0};
int fpow( int a, int b ) {
if( !b ) return 1;
int rtn = fpow(a,b/2);
rtn = int((ll)rtn * rtn % MOD);
if( b & 1 ) rtn = int((ll)rtn * a % MOD);
return rtn;
}
int inv( int a ) {
return fpow(a,MOD-2);
}
int fac[8010], ifac[8010];
void prelude() {
fac[0] = 1;
for( int i = 1; i < 8010; ++i ) fac[i] = int((ll)fac[i-1] * i % MOD);
ifac[8009] = inv(fac[8009]);
for( int i = 8008; i >= 0; --i ) ifac[i] = int((ll)ifac[i+1] * (i+1) % MOD);
}
int C( int a, int b ) {
return int((ll)fac[a] * ifac[a-b] % MOD * ifac[b] % MOD);
}
int main() {
prelude();
int n; scanf( "%d", &n );
int ans = 0;
for( int i = 0; i < n; ++i ) {
int x, y; scanf( "%d%d", &x, &y );
--a[ZERO+x][ZERO+y];
++a[ZERO-x][ZERO-y];
// printf( "C(%d, %d) = %d\n", x+x+y+y, x+x, C(x+x+y+y, x+x) );
ans = (ans - C(x+x+y+y, x+x) + MOD) % MOD;
}
for( int i = 0; i < MAXN; ++i )
for( int j = 0; j < MAXN; ++j ) {
int end = -a[i][j];
a[i][j] = max(a[i][j], 0);
if( i ) a[i][j] = (a[i][j] + a[i-1][j]) % MOD;
if( j ) a[i][j] = (a[i][j] + a[i][j-1]) % MOD;
if( end > 0 ) ans = int((ans + (ll)a[i][j] * end) % MOD);
// if( a[i][j] && i < ZERO+3 && j < ZERO+3 ) printf( "a[%d][%d] = %d\n", i, j, a[i][j] );
}
ans = int((ll)ans * inv(2) % MOD);
printf( "%d\n", ans );
return 0;
}
| codenet | -1 | 1,478 |
s369093714 | p04051 | 1,570,802,161 | cpp | Accepted | 155 | 127,360 | #include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <iostream>
#include <algorithm>
#define MOD 1000000007
using namespace std;
typedef long long ll;
const ll inv2 = 500000004;
template <typename T> inline void getint(T &num){
register int ch, neg = 0;
while(!isdigit(ch = getchar())) if(ch == '-') neg = 1;
num = ch & 15;
while(isdigit(ch = getchar())) num = num * 10 + (ch & 15);
if(neg) num = -num;
}
inline ll fastpow(ll bas, ll ex){
register ll res = 1; bas %= MOD;
for(; ex; ex >>= 1, bas = bas * bas % MOD) if(ex & 1) res = res * bas % MOD;
return res;
}
int N, A[200005], B[200005];
ll f[4005][4005], fac[16005] = {1}, ifac[16005], ans = 0;
inline void Init(){
for(register int i = 1; i <= 16000; i++) fac[i] = fac[i - 1] * i % MOD;
ifac[16000] = fastpow(fac[16000], MOD - 2);
for(register int i = 16000; i >= 1; i--) ifac[i - 1] = ifac[i] * i % MOD;
}
inline ll C(int n, int m) {return fac[n] * ifac[m] % MOD * ifac[n - m] % MOD;}
int main(){
getint(N), Init();
for(register int i = 1; i <= N; i++){
getint(A[i]), getint(B[i]);
f[2001 - A[i]][2001 - B[i]]++;
}
for(register int i = 1; i <= 4001; i++)
for(register int j = 1; j <= 4001; j++)
(f[i][j] += f[i - 1][j] + f[i][j - 1]) %= MOD;
for(register int i = 1; i <= N; i++) (ans += f[2001 + A[i]][2001 + B[i]]) %= MOD;
for(register int i = 1; i <= N; i++) (ans += MOD - C(A[i] + B[i] << 1, A[i] << 1)) %= MOD;
return printf("%lld\n", ans * inv2 % MOD), 0;
} | codenet | -1 | 1,480 |
s995950795 | p04051 | 1,560,115,014 | cpp | Accepted | 182 | 64,640 | #include <bits/stdc++.h>
using namespace std;
const int maxn = 4010, mod = 1e9 + 7;
int n, f[maxn][maxn];
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
cin >> n;
vector<int> a(n);
vector<int> b(n);
for ( int i = 0; i < n; ++ i) {
cin >> a[i] >> b[i];
f[2000 - a[i]][2000 - b[i]] ++;
}
for ( int i = 1; i <= 4000; ++ i) {
f[0][i] = (f[0][i] + f[0][i-1]) % mod;
}
for ( int i = 1; i <= 4000; ++ i) {
f[i][0] = (f[i][0] + f[i-1][0]) % mod;
for ( int k = 1; k <= 4000; ++ k) {
f[i][k] = (f[i][k] + (f[i - 1][k] + f[i][k - 1]) % mod) % mod;
}
}
int ret = 0;
for ( int i = 0; i < n; ++ i) {
ret = (ret + f[a[i]+2000][b[i]+2000]) % mod;
}
function<int(int, int)> _pow = [&](int x, int n) {
int ret = 1;
for ( ; n; n >>= 1, x = 1LL * x * x % mod) {
if( n & 1) {
ret = 1LL * ret * x % mod;
}
}
return ret;
};
vector<int> fac(maxn << 1);
vector<int> ifac(maxn << 1);
for ( int i = fac[0] = 1; i <= 8000; ++ i) {
fac[i] = 1LL * fac[i - 1] * i % mod;
}
ifac[8000] = _pow(fac[8000], mod - 2);
for ( int i = 8000; i; -- i) {
ifac[i - 1] = 1LL * ifac[i] * i % mod;
}
function<int(int, int)> C = [&](int n, int m) {
return 1LL * fac[n] * ifac[m] % mod * ifac[n-m] % mod;
};
for ( int i = 0; i < n; ++ i) {
ret = (ret - C(a[i]+b[i] << 1, a[i] << 1) + mod) % mod;
}
cout << (1LL * ret * (mod + 1 >> 1) % mod) << "\n";
return 0;
} | codenet | -1 | 1,481 |
s805041158 | p04051 | 1,569,908,948 | cpp | Accepted | 194 | 68,096 | #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define mp make_pair
#define ff first
#define ss second
#define pb push_back
#define pf push_front
#define popb pop_back
#define popf pop_front
#define all(v) v.begin(),v.end()
const int maxn = 2e5 + 100, maxval = 2010;
const ll inf = 2e18, mod = 1e9 + 7;
int n, a[maxn], b[maxn], dp[maxval * 2][maxval * 2];
ll fact[maxn], invfact[maxn];
ll powmod(ll a, ll b)
{
if (!b)
return 1LL;
ll tmp = powmod(a, b / 2);
tmp = tmp * tmp % mod;
if (b & 1)
tmp = tmp * a % mod;
return tmp;
}
void addmod(int& a, int b)
{
a += b;
if (a > mod)
a -= mod;
}
ll comb(int n, int r)
{
return fact[n] * (invfact[r] * invfact[n - r] % mod) % mod;
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
fact[0] = 1;
invfact[0] = powmod(fact[0], mod - 2);
for (int i = 1; i < maxn; i++)
fact[i] = fact[i - 1] * i % mod, invfact[i] = powmod(fact[i], mod - 2);
cin >> n;
for (int i = 0; i < n; i++)
{
cin >> a[i] >> b[i];
dp[maxval - a[i]][maxval - b[i]]++;
}
for (int i = 0; i < maxval * 2 - 2; i++)
for (int j = 0; j < maxval * 2 - 2; j++)
addmod(dp[i + 1][j], dp[i][j]), addmod(dp[i][j + 1], dp[i][j]);
ll ans = 0;
for (int i = 0; i < n; i++)
ans = (ans + dp[maxval + a[i]][maxval + b[i]]) % mod;
for (int i = 0; i < n; i++)
ans = (ans - comb(2 * a[i] + 2 * b[i], 2 * a[i]) + mod) % mod;
ans = ans * powmod(2, mod - 2) % mod;
cout << ans << endl;
}
| codenet | -1 | 1,482 |
s840682183 | p04051 | 1,573,532,076 | cpp | Accepted | 193 | 64,512 | #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <algorithm>
using namespace std;
inline int gi() {
register int data = 0, w = 1;
register char ch = 0;
while (!isdigit(ch) && ch != '-') ch = getchar();
if (ch == '-') w = -1, ch = getchar();
while (isdigit(ch)) data = 10 * data + ch - '0', ch = getchar();
return w * data;
}
const int Mod = 1e9 + 7;
const int T = 2001;
int N, f[4005][4005], A[200005], B[200005];
int fpow(int x, int y) {
int res = 1;
while (y) {
if (y & 1) res = 1ll * res * x % Mod;
x = 1ll * x * x % Mod;
y >>= 1;
}
return res;
}
int fac[8005], ifc[8005];
int C(int n, int m) {
if (n < m) return 0;
else return 1ll * fac[n] * ifc[n - m] % Mod * ifc[m] % Mod;
}
int main () {
N = gi();
for (int i = 1; i <= N; i++) A[i] = gi(), B[i] = gi(), f[T - A[i]][T - B[i]]++;
for (int i = 1; i <= 4001; i++)
for (int j = 1; j <= 4001; j++)
f[i][j] = (f[i][j] + (f[i - 1][j] + f[i][j - 1]) % Mod) % Mod;
fac[0] = 1; for (int i = 1; i <= 8000; i++) fac[i] = 1ll * fac[i - 1] * i % Mod;
ifc[8000] = fpow(fac[8000], Mod - 2);
for (int i = 7999; ~i; i--) ifc[i] = 1ll * ifc[i + 1] * (i + 1) % Mod;
int ans = 0;
for (int i = 1; i <= N; i++) {
ans = (ans + f[A[i] + T][B[i] + T]) % Mod;
ans = (ans - C((A[i] + B[i]) << 1, A[i] << 1) + Mod) % Mod;
}
ans = 1ll * ans * fpow(2, Mod - 2) % Mod;
printf("%d\n", ans);
return 0;
} | codenet | -1 | 1,483 |
s549323976 | p04051 | 1,573,770,997 | cpp | Accepted | 140 | 64,768 | #include<bits/stdc++.h>
#define LL long long
#define RG register
using namespace std;
template<class T> T gi() {
T x = 0; bool f = 0; char c = getchar();
while (c != '-' && (c < '0' || c > '9')) c = getchar();
if (c == '-') f = 1, c = getchar();
while (c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();
return f ? -x : x;
}
const int N = 200010, Mod = 1e9 + 7;
int A[N], B[N], n, fac[8010], ifac[8010];
int C(int n, int m) {
if (n < m) return 0;
return 1ll * fac[n] * ifac[m] % Mod * ifac[n - m] % Mod;
}
int fpow(int a, int b) {
int res = 1;
for (; b; b >>= 1, a = 1ll * a * a % Mod)
if (b & 1) res = 1ll * res * a % Mod;
return res;
}
int f[4010][4010];
int main() {
//freopen(".in", "r", stdin);
//freopen(".out", "w", stdout);
n = gi<int>();
for (int i = 1; i <= n; i++) {
A[i] = gi<int>(), B[i] = gi<int>();
f[2000 - A[i]][2000 - B[i]]++;
}
fac[0] = 1;
for (int i = 1; i <= 8000; i++) fac[i] = 1ll * fac[i - 1] * i % Mod;
ifac[8000] = fpow(fac[8000], Mod - 2);
for (int i = 8000; i >= 1; i--) ifac[i - 1] = 1ll * ifac[i] * i % Mod;
for (int i = 0; i <= 4000; i++)
for (int j = 0; j <= 4000; j++) {
if (i) f[i][j] = (f[i][j] + f[i - 1][j]) % Mod;
if (j) f[i][j] = (f[i][j] + f[i][j - 1]) % Mod;
}
int ans = 0;
for (int i = 1; i <= n; i++) {
ans = (ans + f[A[i] + 2000][B[i] + 2000]) % Mod;
ans = (ans - C(A[i] + A[i] + B[i] + B[i], A[i] + A[i]) + Mod) % Mod;
}
printf("%d\n", 1ll * ans * fpow(2, Mod - 2) % Mod);
return 0;
}
| codenet | -1 | 1,485 |
s218837826 | p04051 | 1,506,612,668 | cpp | Accepted | 212 | 65,280 | #include <bits/stdc++.h>
using namespace std;
#define fo(i,s,t) for(int i = s; i <= t; ++ i)
#define fd(i,s,t) for(int i = s; i >= t; -- i)
#define bf(i,s) for(int i = head[s]; i; i = e[i].next)
#define mp make_pair
#define fi first
#define se second
#define pii pair<int,int>
#define pb push_back
#define VI vector<int>
#define sf scanf
#define pf printf
#define fp freopen
#define SZ(x) ((int)(x).size())
#define IF_DEBUG 0
typedef long long ll;
typedef double db;
typedef unsigned long long ull;
const int inf = 1<<30;
const ll INF = 1ll<<60;
const db Inf = 1e20;
const db eps = 1e-9;
void gmax(int &a,int b){a = (a > b ? a : b);}
void gmin(int &a,int b){a = (a < b ? a : b);}
const int maxn = 200050;
const int maxm = 2005;
const int P = 1e9+7;
int f[maxm<<1][maxm<<1];
int N, A[maxn], B[maxn], Fac[maxn], Ans;
int inv(int a)
{
int ans = 1, b = P-2;
while(b)
{
if(b&1) ans = (1ll*ans*a)%P;
b >>= 1; a = (1ll*a*a)%P;
}
return ans;
}
int C(int n,int m)
{
return (((1ll*Fac[n]*inv(Fac[m]))%P)*inv(Fac[n-m]))%P;
}
int main()
{
sf("%d",&N);
fo(i,1,N) sf("%d%d",&A[i],&B[i]);
fo(i,1,N) f[-A[i]+maxm][-B[i]+maxm] ++;
fo(i,-2000,2000) fo(j,-2000,2000)
f[i+maxm][j+maxm] = (1ll*f[i+maxm][j+maxm]+f[i-1+maxm][j+maxm]+f[i+maxm][j-1+maxm])%P;
fo(i,1,N) Ans = (1ll*Ans + f[A[i]+maxm][B[i]+maxm])%P;
Fac[0] = 1; fo(i,1,maxn-1) Fac[i] = (1ll*Fac[i-1]*i)%P;
fo(i,1,N) Ans = ((1ll*Ans - C(A[i]*2+B[i]*2,A[i]*2))%P+P)%P;
Ans = 1ll*Ans*inv(2)%P;
pf("%d\n",Ans);
return 0;
} | codenet | -1 | 1,486 |
s944375841 | p04051 | 1,506,086,123 | cpp | Accepted | 209 | 189,824 | #include<cstdio>
#include<iostream>
#include<algorithm>
#include<ctime>
#include<cstdlib>
#include<algorithm>
#include<cmath>
#include<queue>
#include<cstring>
#include<map>
#include<vector>
#include<set>
#define rep(i,j,k) for(register int i = j; i <= k; i++)
#define dow(i,j,k) for(register int i = j; i >= k; i--)
#define fi first
#define se second
//#define P pair<ll,ll>
#define mp(a,b) make_pair(a,b)
#define ll long long
#define ull unsigned long long
using namespace std;
inline int read() {
int s = 0, t = 1; char c = getchar();
while( !isdigit(c) ) { if( c == '-' ) t = -1; c = getchar(); }
while( isdigit(c) ) s = s * 10 + c - 48, c = getchar();
return s * t;
}
const int N = 4008, M = 2001, p = 1e9+7;
inline void _(ll &x) { if( x >= p ) x -= p; }
ll ans = 0, f[N][N], g[N][N], fac[N<<1] = {1}, ni[N<<1] = {1,1};
inline ll C(int n,int m) {
return fac[n] * ni[m] % p * ni[n-m] % p;
}
int main() {
int n = read(), x, y, mx = 0, my = 0;
rep(i,1,8000) fac[i] = fac[i-1] * i % p;
rep(i,2,8000) ni[i] = (p - p / i) * ni[p % i] % p;
rep(i,2,8000) ni[i] = ni[i] * ni[i-1] % p;
rep(i,1,n) {
mx = max(mx,x = read()), my = max(my,y = read());
f[M-x][M-y]++;
g[M+x][M+y]++;
(ans -= C((x+y)<<1,x<<1)) %= p;
}
rep(i,M-mx,M+mx) {
rep(j,M-my,M+my) {
_(f[i][j]+=f[i-1][j]);
_(f[i][j]+=f[i][j-1]);
}
}
rep(i,1+M,mx+M) {
rep(j,1+M,my+M) {
(ans += (ll)g[i][j] * f[i][j]) %= p;
}
}
cout<<(ans + p) % p * ((p + 1) / 2) % p<<endl;
return 0;
} | codenet | -1 | 1,487 |
s773800224 | p04051 | 1,575,526,324 | cpp | Accepted | 233 | 128,256 | #include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 5;
const int M = 4e3 + 5;
const int _C = 2000;
const int P = 1e9 + 7;
typedef long long LL;
#define f(x, y) F[(x) + _C + 1][(y) + _C + 1]
#define m(x, y) wap[(x) + _C + 1][(y) + _C + 1]
#define C(x, y) ((x >= y && y >= 0) ? (frac[x] * inv_frac[(x) - (y)] % P * inv_frac[y] % P) : 0)
int wap[M][M], n;
int F[M][M], ans;
LL frac[N], inv_frac[N];
inline LL ksm(LL base, LL x) {
LL res = 1;
while(x) {
if(x & 1) res *= base, res %= P;
x >>= 1, base *= base, base %= P;
}
return res;
}
void init() {
int a, b;
scanf("%d", &n);
frac[0] = 1;
for(int i = 1; i < N; i++) frac[i] = frac[i - 1] * i % P;
inv_frac[N - 1] = ksm(frac[N - 1], P - 2);
for(int i = N - 2; i >= 0; i--) inv_frac[i] = inv_frac[i + 1] * (i + 1) % P;
for(int i = 1; i <= n; i++) {
scanf("%d%d", &a, &b);
ans += P - C(a + a + b + b, a + a);
ans %= P;
m(-a, -b) ++;
f(-a, -b) ++;
m(a, b) --;
}
for(int i = -_C; i <= _C; i++) {
for(int j = -_C; j <= _C; j++) {
f(i, j) += (f(i - 1, j) + f(i, j - 1)) % P;
f(i, j) %= P;
//if(f(i, j)) printf("f(%d, %d) = %lld\n", i, j, f(i, j));
if(m(i, j) < 0) ans += (LL)-m(i, j) * f(i, j) % P, ans %= P;
}
}
if(ans % 2 == 0) ans /= 2;
else ans += P, ans /= 2;
cout << ans << endl;
}
int main() {
init();
return 0;
}
| codenet | -1 | 1,488 |
s975430492 | p04051 | 1,485,402,244 | cpp | Accepted | 228 | 64,640 | #include <bits/stdc++.h>
#define LL long long
#define INF 0x3f3f3f3f // -Wall
using namespace std;
template<class T> inline
void read(T& x) {
int f = 1; x = 0;
char ch = getchar();
while (ch < '0' || ch > '9') {if (ch == '-') f = -1; ch = getchar();}
while (ch >= '0' && ch <= '9') {x = x * 10 + ch - '0'; ch = getchar();}
x *= f;
}
/*============ Header Template ============*/
const int N = 200000 + 5;
const int mo = 1000000007;
const int M = 2000;
int n;
int a[N], b[N];
int c[(M << 1) + 5][(M << 1) + 5];
LL f[N], inv[N];
void exgcd(LL a, LL b, LL &x, LL &y) {
if (b == 0) {x = 1, y = 0; return;}
exgcd(b, a % b, y, x);
y -= x * (a / b);
}
LL C(int n, int m) {return m > n ? 0 : f[n] * inv[m] % mo * inv[n - m] % mo;}
void pre() {
f[0] = 1;
for (int i = 1; i <= 8000; i++) f[i] = f[i - 1] * i % mo;
LL y; exgcd(f[8000], mo, inv[8000], y);
for (int i = 7999; i >= 0; i--) inv[i] = inv[i + 1] * (i + 1) % mo;
}
int main() {
read(n); pre();
for (int i = 1; i <= n; i++) read(a[i]), read(b[i]);
for (int i = 1; i <= n; i++) c[-b[i] + M][-a[i] + M]++;
for (int i = 0; i <= M * 2; i++)
for (int j = 0; j <= M * 2; j++) {
(c[i][j + 1] += c[i][j]) %= mo;
(c[i + 1][j] += c[i][j]) %= mo;
}
LL ans = 0;
for (int i = 1; i <= n; i++) (ans += c[b[i] + M][a[i] + M]) %= mo;
for (int i = 1; i <= n; i++) {
LL tmp = C(a[i] + b[i] + a[i] + b[i], a[i] + a[i]);
(ans -= tmp) %= mo;
}
ans = ans * inv[2] % mo;
printf("%lld\n", (ans + mo) % mo);
return 0;
} | codenet | -1 | 1,488 |
s109992288 | p04051 | 1,567,886,202 | cpp | Accepted | 152 | 132,096 | #include <bits/stdc++.h>
#define int long long
using namespace std;
const int N = 2e5 + 10;
const int mod = 1e9 + 7;
int n;
int inv[N], fac[N], f[4010][4010], a[N], b[N];
template<class T>inline void read(T &x) {
x = 0; int f = 0; char ch = getchar();
while (!isdigit(ch)) f |= (ch == '-'), ch = getchar();
while (isdigit(ch)) x = x * 10 + ch - '0', ch = getchar();
x = f ? -x : x;
return;
}
int qpow(int a, int b) {
int ans = 1;
while (b) {
if (b & 1) ans = (ans * a) % mod;
a = (a * a) % mod, b >>= 1;
}
return ans;
}
void init() {
fac[0] = 1;
for (int i = 1; i <= N - 10; ++i) fac[i] = fac[i - 1] * i % mod;
inv[N - 10] = qpow(fac[N - 10], mod - 2);
for (int i = N - 11; i >= 0; --i) inv[i] = inv[i + 1] * (i + 1) % mod;
}
int C(int x, int y) {
return fac[x] * inv[y] % mod * inv[x - y] % mod;
}
signed main() {
init();
read(n);
for (int i = 1; i <= n; ++i) {
read(a[i]), read(b[i]);
f[2001 - a[i]][2001 - b[i]]++;
}
for (int i = 1; i <= 4001; ++i)
for (int j = 1; j <= 4001; ++j) {
f[i][j] = (f[i][j] + f[i - 1][j]) % mod;
f[i][j] = (f[i][j] + f[i][j - 1]) % mod;
}
int ans = 0;
for (int i = 1; i <= n; ++i) ans = (ans + f[2001 + a[i]][2001 + b[i]]) % mod;
for (int i = 1; i <= n; ++i) ans = (ans - C(a[i] + a[i] + b[i] + b[i], a[i] + a[i]) + mod) % mod;
printf("%lld\n", ans * qpow(2, mod - 2) % mod);
return 0;
} | codenet | -1 | 1,493 |
s109992288 | p04051 | 1,567,886,202 | cpp | Accepted | 152 | 132,096 | #include <bits/stdc++.h>
#define int long long
using namespace std;
const int N = 2e5 + 10;
const int mod = 1e9 + 7;
int n;
int inv[N], fac[N], f[4010][4010], a[N], b[N];
template<class T>inline void read(T &x) {
x = 0; int f = 0; char ch = getchar();
while (!isdigit(ch)) f |= (ch == '-'), ch = getchar();
while (isdigit(ch)) x = x * 10 + ch - '0', ch = getchar();
x = f ? -x : x;
return;
}
int qpow(int a, int b) {
int ans = 1;
while (b) {
if (b & 1) ans = (ans * a) % mod;
a = (a * a) % mod, b >>= 1;
}
return ans;
}
void init() {
fac[0] = 1;
for (int i = 1; i <= N - 10; ++i) fac[i] = fac[i - 1] * i % mod;
inv[N - 10] = qpow(fac[N - 10], mod - 2);
for (int i = N - 11; i >= 0; --i) inv[i] = inv[i + 1] * (i + 1) % mod;
}
int C(int x, int y) {
return fac[x] * inv[y] % mod * inv[x - y] % mod;
}
signed main() {
init();
read(n);
for (int i = 1; i <= n; ++i) {
read(a[i]), read(b[i]);
f[2001 - a[i]][2001 - b[i]]++;
}
for (int i = 1; i <= 4001; ++i)
for (int j = 1; j <= 4001; ++j) {
f[i][j] = (f[i][j] + f[i - 1][j]) % mod;
f[i][j] = (f[i][j] + f[i][j - 1]) % mod;
}
int ans = 0;
for (int i = 1; i <= n; ++i) ans = (ans + f[2001 + a[i]][2001 + b[i]]) % mod;
for (int i = 1; i <= n; ++i) ans = (ans - C(a[i] + a[i] + b[i] + b[i], a[i] + a[i]) + mod) % mod;
printf("%lld\n", ans * qpow(2, mod - 2) % mod);
return 0;
} | codenet | -1 | 1,493 |
s625951607 | p04051 | 1,577,778,891 | cpp | Accepted | 147 | 64,752 | #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define F first
#define S second
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define SZ(x) (int)x.size()
//#define int ll
const int MOD = 1e9 + 7;
void add(int &a, int b) {
a += b;
if (a >= MOD) {
a -= MOD;
}
}
void sub(int &a, int b) {
a -= b;
if (a < 0) {
a += MOD;
}
}
int mult(int a, int b) {
return (a * 1ll * b) % MOD;
}
int b_pow(int a, int b) {
if (!b) {
return 1;
}
if (b & 1) {
return mult(a, b_pow(a, b - 1));
}
return b_pow(mult(a, a), b >> 1);
}
const int N = 4010;
int dp[N][N], f[2 * N], rf[2 * N];
int C(int n, int k) {
if (n < 0 || k < 0 || n < k) {
return 0;
}
return mult(f[n], mult(rf[k], rf[n - k]));
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
f[0] = 1;
for (int i = 1; i <= 8000; i++) {
f[i] = mult(f[i - 1], i);
}
for (int i = 0; i <= 8000; i++) {
rf[i] = b_pow(f[i], MOD - 2);
}
int n;
cin >> n;
vector<pair<int, int>> pr;
for (int i = 1; i <= n; i++) {
int a, b;
cin >> a >> b;
pr.pb({a, b});
dp[2000 - a][2000 - b]++;
}
for (int i = 0; i <= 4000; i++) {
for (int j = 0; j <= 4000; j++) {
add(dp[i + 1][j], dp[i][j]);
add(dp[i][j + 1], dp[i][j]);
}
}
int ans = 0;
for (auto it : pr) {
add(ans, dp[it.F + 2000][it.S + 2000]);
}
for (auto it : pr) {
sub(ans, C(2 * it.F + 2 * it.S, 2 * it.S));
}
ans = mult(ans, b_pow(2, MOD - 2));
cout << ans << '\n';
} | codenet | -1 | 1,496 |
s248916063 | p04051 | 1,595,292,401 | cpp | Accepted | 156 | 68,096 | #include <iostream>
#include <cstdio>
#include <algorithm>
template <typename Tp>
inline void read(Tp &x) {
x = 0;
bool f = true; char ch = getchar();
for ( ; ch < '0' || ch > '9'; ch = getchar()) f ^= ch == '-';
for ( ; ch >= '0' && ch <= '9'; ch = getchar()) x = x * 10 + (ch ^ 48);
x = f ? x : -x;
}
const int N = 2e5 + 7, M = 4e3 + 7, P = 1e9 + 7;
int A[N], B[N], F[M][M], Fac[M * 2], iFac[M * 2];
inline int Power(int a, int x) {
int res = 1;
while (x) {
if (x & 1) res = 1LL * res * a % P;
a = 1LL * a * a % P;
x >>= 1;
}
return res;
}
inline int Inv(int x) {
return Power(x, P - 2);
}
inline int C(int n, int m) {
if (m < 0 || m > n) return 0;
return 1LL * Fac[n] * iFac[n - m] % P * iFac[m] % P;
}
int main() {
Fac[0] = 1;
for (int i = 1; i < M * 2; ++i) Fac[i] = 1LL * Fac[i - 1] * i % P;
iFac[2 * M - 1] = Inv(Fac[2 * M - 1]);
for (int i = 2 * M - 2; i >= 0; --i) iFac[i] = 1LL * iFac[i + 1] * (i + 1) % P;
int n;
read(n);
for (int i = 1; i <= n; ++i) read(A[i]), read(B[i]), ++F[-A[i] + M / 2][-B[i] + M / 2];
for (int i = 1; i < M; ++i)
for (int j = 1; j < M; ++j) F[i][j] = (1LL * F[i][j] + F[i - 1][j] + F[i][j - 1]) % P;
int Ans = 0;
for (int i = 1; i <= n; ++i) {
Ans = (Ans + F[A[i] + M / 2][B[i] + M / 2]) % P;
Ans = (Ans + P - C(2 * (A[i] + B[i]), 2 * A[i])) % P;
}
printf("%lld\n", 1LL * Ans * Inv(2) % P);
return 0;
} | codenet | -1 | 1,497 |
s331848841 | p04051 | 1,508,963,040 | cpp | Accepted | 133 | 65,792 | #include <bits/stdc++.h>
using namespace std;
const int N = 202020;
const int M = 4040;
const int MOD = 1000000007;
const int s = 2020;
typedef long long ll;
inline char get(void) {
static char buf[100000], *S = buf, *T = buf;
if (S == T) {
T = (S = buf) + fread(buf, 1, 100000, stdin);
if (S == T) return EOF;
}
return *S++;
}
template<typename T>
inline void read(T &x) {
static char c; x = 0; int sgn = 0;
for (c = get(); c < '0' || c > '9'; c = get()) if (c == '-') sgn = 1;
for (; c >= '0' && c <= '9'; c = get()) x = x * 10 + c - '0';
if (sgn) x = -x;
}
int a[N], b[N];
int f[M][M];
int fac[N], inv[N];
int n, m, ans;
inline void Add(int &x, int a) {
x += a; while (x >= MOD) x -= MOD;
}
inline int C(int n, int m) {
return (ll)fac[n + m] * inv[n] % MOD * inv[m] % MOD;
}
int main(void) {
read(n);
for (int i = 1; i <= n; i++) {
read(a[i]); read(b[i]);
++f[s - a[i]][s - b[i]];
}
for (int i = 1; i < M; i++)
for (int j = 1; j < M; j++) {
Add(f[i][j], f[i - 1][j]);
Add(f[i][j], f[i][j - 1]);
}
inv[1] = 1;
for (int i = 2; i <= 10000; i++)
inv[i] = (ll)(MOD - MOD / i) * inv[MOD % i] % MOD;
fac[0] = inv[0] = 1;
for (int i = 1; i <= 10000; i++) {
fac[i] = (ll)i * fac[i - 1] % MOD;
inv[i] = (ll)inv[i] * inv[i - 1] % MOD;
}
for (int i = 1; i <= n; i++) {
Add(ans, f[s + a[i]][s + b[i]]);
Add(ans, MOD - C(a[i] << 1, b[i] << 1));
}
ans = (ll)ans * (MOD + 1) / 2 % MOD;
cout << ans << endl;
return 0;
} | codenet | -1 | 1,498 |
s004039560 | p04051 | 1,591,661,976 | cpp | Accepted | 123 | 66,048 | #include<bits/stdc++.h>
using namespace std;
#define N 200000 + 5
#define M 4000 + 5
#define Mod 1000000007
#define rep(i, l, r) for(int i = l; i <= r; ++i)
int n, del, ans, a[N], b[N], f[N], inv[N], dp[M][M];
int read(){
char c; int x = 0, f = 1;
c = getchar();
while(c > '9' || c < '0'){ if(c == '-') f = -1; c = getchar();}
while(c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();
return x * f;
}
int c(int x){ return x + del;}
int Inc(int a, int b){ return (a += b) >= Mod ? a - Mod : a;}
int Dec(int a, int b){ return (a -= b) < 0 ? a + Mod : a;}
int Mul(int a, int b){ return 1ll * a * b % Mod;}
int Qpow(int a, int b){
int ans = 1;
while(b){
if(b & 1) ans = Mul(ans, a);
a = Mul(a, a), b >>= 1;
}
return ans;
}
int C(int n, int m){
if(m > n) return 0;
return Mul(f[n], Mul(inv[m], inv[n - m]));
}
int main(){
f[0] = inv[0] = 1;
rep(i, 1, N - 5) f[i] = Mul(f[i - 1], i), inv[i] = Qpow(f[i], Mod - 2);
n = read(), del = 2000;
rep(i, 1, n) a[i] = read(), b[i] = read(), dp[c(-a[i])][c(-b[i])] += 1;
rep(i, -del, del) rep(j, -del, del){
if(i > -del) dp[c(i)][c(j)] = Inc(dp[c(i)][c(j)], dp[c(i - 1)][c(j)]);
if(j > -del) dp[c(i)][c(j)] = Inc(dp[c(i)][c(j)], dp[c(i)][c(j - 1)]);
}
rep(i, 1, n) ans = Inc(ans, dp[c(a[i])][c(b[i])]);
rep(i, 1, n) ans = Dec(ans, C(a[i] + a[i] + b[i] + b[i], a[i] + a[i]));
ans = Mul(ans, Qpow(2, Mod - 2));
printf("%d", ans);
return 0;
} | codenet | -1 | 1,499 |
s326400701 | p04051 | 1,554,926,246 | cpp | Accepted | 102 | 64,512 | #include<cstdio>
#include<cstring>
#include<cmath>
#include<cstdlib>
#include<algorithm>
#include<set>
#define ll long long
#define mod 1000000007
#define Mod1(x) (x>=mod?x-mod:x)
#define Mod2(x) (x<0?x+mod:x)
#define maxn 200010
inline ll read()
{
ll x=0; char c=getchar(),f=1;
for(;c<'0'||'9'<c;c=getchar())if(c=='-')f=-1;
for(;'0'<=c&&c<='9';c=getchar())x=x*10+c-'0';
return x*f;
}
inline void write(ll x)
{
static int buf[20],len; len=0;
if(x<0)x=-x,putchar('-');
for(;x;x/=10)buf[len++]=x%10;
if(!len)putchar('0');
else while(len)putchar(buf[--len]+'0');
}
inline void writeln(ll x){write(x); putchar('\n');}
inline void writesp(ll x){write(x); putchar(' ');}
const int size=4010,inv2=(mod+1)>>1;
int fac[2*size],inv[2*size];
int dp[size][size];
int a[maxn],b[maxn];
int n,tot;
inline ll power(ll a,ll b)
{
ll ans=1;
for(;b;b>>=1,a=a*a%mod)
if(b&1)ans=ans*a%mod;
return ans;
}
inline ll C(ll n,ll m){return (ll)fac[n]*inv[m]%mod*inv[n-m]%mod;}
int main()
{
n=read();
for(int i=1;i<=n;i++){
a[i]=read(); b[i]=read();
++dp[2000-a[i]][2000-b[i]];
}
for(int i=0;i<=4000;i++)
for(int j=0;j<=4000;j++){
if(i)dp[i][j]=Mod1(dp[i][j]+dp[i-1][j]);
if(j)dp[i][j]=Mod1(dp[i][j]+dp[i][j-1]);
}
int ans=0;
for(int i=1;i<=n;i++)
ans=Mod1(ans+dp[2000+a[i]][2000+b[i]]);
fac[0]=inv[0]=1;
for(int i=1;i<=8000;i++)
fac[i]=(ll)fac[i-1]*i%mod,inv[i]=power(fac[i],mod-2);
for(int i=1;i<=n;i++)
ans=Mod2(ans-C(2*a[i]+2*b[i],2*a[i]));
writeln((ll)ans*inv2%mod);
return 0;
} | codenet | -1 | 1,499 |
s344129827 | p04051 | 1,523,083,392 | cpp | Accepted | 252 | 99,072 | #include<bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
const int MX = 4010;
const int offset = 2000;
int exp(int x, int n) {
int ret = 1;
while(n) {
if(n & 1) ret = 1LL * ret * x % mod;
x = 1LL * x * x % mod;
n >>= 1;
}
return ret;
}
int inv(int x) {
return exp(x, mod - 2);
}
int fact[10010], invf[10010];
int comb(int n, int k) {
return 1LL * fact[n] * invf[k] % mod * invf[n - k] % mod;
}
int N;
int A[200010], B[200010];
int chk[4010][4010];
int cc[4010][4010];
int dp(int x, int y) {
if(x >= MX || y >= MX) return 0;
int &ret = cc[x][y];
if(ret != -1) return ret;
ret = 0;
ret += chk[x][y];
ret %= mod;
ret += dp(x + 1, y);
ret %= mod;
ret += dp(x, y + 1);
ret %= mod;
return ret;
}
int main() {
fact[0] = 1;
for(int i = 1; i < 10010; i++) {
fact[i] = 1LL * fact[i - 1] * i % mod;
}
for(int i = 0; i < 10010; i++) {
invf[i] = inv(fact[i]);
}
scanf("%d", &N);
for(int i = 0; i < N; i++) {
scanf("%d %d", &A[i], &B[i]);
chk[ A[i] + offset ][ B[i] + offset ]++;
}
memset(cc, -1, sizeof(cc));
int ans = 0;
for(int i = 0; i < N; i++) {
ans += dp(-A[i] + offset, -B[i] + offset);
ans %= mod;
}
for(int i = 0; i < N; i++) {
ans += mod - comb(2 * A[i] + 2 * B[i], 2 * A[i]);
ans %= mod;
}
ans = 1LL * ans * inv(2) % mod;
ans %= mod;
printf("%d", ans);
}
| codenet | -1 | 1,499 |
s299467498 | p04051 | 1,586,136,744 | cpp | Accepted | 151 | 195,328 | #include<bits/stdc++.h>
#define mod 1000000007
#define int long long
#define BASE 3000
using namespace std;
inline int read(){
int res=0;
char c;
bool zf=0;
while(((c=getchar())<'0'||c>'9')&&c!= '-');
if(c=='-')zf=1;
else res=c-'0';
while((c=getchar())>='0'&&c<='9')res=(res<<3)+(res<<1)+c-'0';
if(zf)return -res;
return res;
}
struct op{
int a,b;
}data[200005];
int dp[6005][6005];
int frac[10005],inv[10005];
inline int C(int a,int b){
return frac[a]*inv[a-b]%mod*inv[b]%mod;
}
inline int solve(int x,int y=mod-2,int MOD=mod){
int res=1;
while(y){
if(y&1)res=res*x%mod;
x=x*x%mod;
y>>=1;
}
return res;
}
signed main(){
int n=read();
for(register int i=1;i<=n;i++)data[i].a=read(),data[i].b=read();
for(register int i=1;i<=n;i++)dp[BASE-data[i].a][BASE-data[i].b]++;
int Maxx=-2e9,Maxy=-2e9;
for(register int i=1;i<=n;i++)Maxx=max(Maxx,data[i].a),Maxy=max(Maxy,data[i].b);
for(register int i=-Maxx;i<=Maxx;i++)for(register int j=-Maxy;j<=Maxy;j++)dp[BASE+i][BASE+j]=(dp[BASE+i][BASE+j]+dp[BASE+i-1][BASE+j]+dp[BASE+i][BASE+j-1])%mod;
int ans=0;
for(register int i=1;i<=n;i++)ans=(ans+dp[BASE+data[i].a][BASE+data[i].b])%mod;
int temp=(Maxx+Maxy)<<1;
frac[1]=1;for(register int i=2;i<=temp;i++)frac[i]=frac[i-1]*i%mod;
inv[temp]=solve(frac[temp]);for(register int i=temp-1;i>=1;i--)inv[i]=inv[i+1]*(i+1)%mod;
for(register int i=1;i<=n;i++)
ans=(ans-C((data[i].a+data[i].b)<<1,data[i].a<<1)+mod)%mod;
cout<<ans*solve(2)%mod;
return 0;
} | codenet | -1 | 1,500 |
s338393840 | p04051 | 1,573,418,653 | cpp | Accepted | 143 | 129,152 | // ===================================
// author: M_sea
// website: http://m-sea-blog.com/
// ===================================
#include <algorithm>
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>
#include <vector>
#include <cmath>
#define re register
using namespace std;
inline int read() {
int X=0,w=1; char c=getchar();
while (c<'0'||c>'9') { if (c=='-') w=-1; c=getchar(); }
while (c>='0'&&c<='9') X=X*10+c-'0',c=getchar();
return X*w;
}
const int mod=1e9+7;
inline int qpow(int a,int b) { int c=1;
for (;b;b>>=1,a=1ll*a*a%mod) if (b&1) c=1ll*c*a%mod;
return c;
}
const int N=200000+10,SIZE=2001,L=(SIZE<<2)+10;
int fac[L],ifac[L];
inline void init(int n) {
fac[0]=1;
for (re int i=1;i<=n;++i) fac[i]=1ll*fac[i-1]*i%mod;
ifac[n]=qpow(fac[n],mod-2);
for (re int i=n;i;--i) ifac[i-1]=1ll*ifac[i]*i%mod;
}
inline int C(int n,int m) {
return 1ll*fac[n]*ifac[m]%mod*ifac[n-m]%mod;
}
int n,a[N],b[N],dp[L][L];
int main() { init(SIZE<<2);
n=read();
for (re int i=1;i<=n;++i) {
a[i]=read(),b[i]=read();
++dp[SIZE-a[i]][SIZE-b[i]];
}
for (re int i=1;i<=SIZE<<1;++i)
for (re int j=1;j<=SIZE<<1;++j)
dp[i][j]=(dp[i][j]+dp[i-1][j]+dp[i][j-1])%mod;
int ans=0;
for (re int i=1;i<=n;++i) {
ans=(ans+dp[SIZE+a[i]][SIZE+b[i]])%mod;
ans=(ans-C(a[i]+a[i]+b[i]+b[i],a[i]+a[i])+mod)%mod;
}
printf("%lld\n",1ll*ans*qpow(2,mod-2)%mod);
return 0;
}
| codenet | -1 | 1,502 |
s092671508 | p04051 | 1,468,729,420 | cpp | Accepted | 673 | 147,840 | #include <bits/stdc++.h>
using namespace std;
const long long mod = 1e9 + 7;
long long modpow(long long a, long long b) {
if (b == 0) return 1;
return modpow(a * a % mod, b / 2) * (b & 1 ? a : 1) % mod;
}
long long modinv(long long a) {
return modpow(a, mod - 2);
}
vector<long long> fact, inv_fact;
void init_fact(int n) {
fact.resize(n);
fact[0] = 1;
for (int i = 1; i < n; i++) {
fact[i] = i * fact[i - 1] % mod;
}
inv_fact.resize(n);
inv_fact[n - 1] = modinv(fact[n - 1]);
for (int i = n - 2; i >= 0; i--) {
inv_fact[i] = (i + 1) * inv_fact[i + 1] % mod;
}
}
long long nPr(int n, int r) {
if (n < r || n < 0 || r < 0) return 0;
return fact[n] * inv_fact[n - r] % mod;
}
long long nCr(int n, int r) {
if (n < r || n < 0 || r < 0) return 0;
return fact[n] * inv_fact[r] % mod * inv_fact[n - r] % mod;
}
long long nHr(int n, int r) {
if (n == 0 && r == 0) return 1;
return nCr(n + r - 1, r);
}
int main() {
init_fact(101010);
int n;
cin >> n;
vector<int> a(n), b(n);
static long long dp[4400][4400];
for (int i = 0; i < n; i++) {
scanf("%d %d", &a[i], &b[i]);
dp[2010 - a[i]][2010 - b[i]]++;
}
for (int i = 0; i < 4200; i++) {
for (int j = 0; j < 4200; j++) {
(dp[i + 1][j] += dp[i][j]) %= mod;
(dp[i][j + 1] += dp[i][j]) %= mod;
}
}
long long ans = 0;
for (int i = 0; i < n; i++) {
(ans += dp[2010 + a[i]][2010 + b[i]]) %= mod;
(ans += mod - nCr(a[i] * 2 + b[i] * 2, a[i] * 2)) %= mod;
}
ans = ans * modinv(2) % mod;
cout << ans << endl;
} | codenet | -1 | 1,507 |
s916167839 | p04051 | 1,578,600,208 | cpp | Accepted | 212 | 65,024 | #include<bits/stdc++.h>
using namespace std;
const int N = 200 * 1000 + 20, mod = 1e9 + 7, X = 4000 + 20;
int x[N], y[N], dp[X][X], fact[N], factRev[N], n, ans;
int sum(int a, int b) {
return ((1LL * a + b) % mod + mod) % mod;
}
int mul(int a, int b) {
return ((1LL * a * b) % mod + mod) % mod;
}
int pw(int a, int b) {
int res = 1, tmp = a;
while (b) {
if (b & 1)
res = mul(res, tmp);
tmp = mul(tmp, tmp);
b >>= 1;
}
return res;
}
int c(int a, int b) {
return mul(fact[a], mul(factRev[b], factRev[a - b]));
}
int main() {
ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);
cin >> n;
for (int i = 0; i < n; i++)
cin >> x[i] >> y[i];
fact[0] = 1;
for (int i = 1; i <= 8000; i++)
fact[i] = mul(fact[i - 1], i);
factRev[8000] = pw(fact[8000], mod - 2);
for (int i = 8000 - 1; ~i; i--)
factRev[i] = mul(factRev[i + 1], i + 1);
for (int i = 0; i < n; i++)
dp[2000 - x[i]][2000 - y[i]]++;
for (int i = 0; i <= 4000; i++)
for (int j = 0; j <= 4000; j++) {
if (i)
dp[i][j] = sum(dp[i][j], dp[i - 1][j]);
if (j)
dp[i][j] = sum(dp[i][j], dp[i][j - 1]);
}
for (int i = 0; i < n; i++)
ans = sum(ans, dp[x[i] + 2000][y[i] + 2000]);
for (int i = 0; i < n; i++)
ans = sum(ans, -c((x[i] + y[i]) * 2, x[i] * 2));
ans = mul(ans, pw(2, mod - 2));
return cout << ans << "\n", 0;
} | codenet | -1 | 1,510 |
s796623598 | p04051 | 1,507,653,141 | cpp | Accepted | 169 | 96,640 | #include<bits/stdc++.h>
using namespace std;
#define MAXN 200005
#define MAXM 4005
#define DELTA 2000
#define LIMIT 4000
#define P 1000000007
template <typename T> void read(T &x) {
x = 0; int f = 1;
char c = getchar();
for (; !isdigit(c); c = getchar()) if (c == '-') f = -f;
for (; isdigit(c); c = getchar()) x = x * 10 + c - '0';
x *= f;
}
int a[MAXN], b[MAXN];
int cnt[MAXM][MAXM];
int key[MAXM][MAXM];
long long fac[MAXM * 2], inv[MAXM * 2];
long long power(long long x, long long y) {
if (y == 0) return 1;
long long tmp = power(x, y / 2);
if (y % 2 == 0) return tmp * tmp % P;
else return tmp * tmp % P * x % P;
}
long long getc(int x, int y) {
return fac[x] * inv[y] % P * inv[x - y] % P;
}
int main() {
int N = MAXM * 2 - 1;
fac[0] = 1;
for (int i = 1; i <= N; i++)
fac[i] = fac[i - 1] * i % P;
inv[N] = power(fac[N], P - 2);
for (int i = N - 1; i >= 0; i--)
inv[i] = inv[i + 1] * (i + 1) % P;
int n; read(n);
for (int i = 1; i <= n; i++) {
read(a[i]), read(b[i]);
key[a[i] + DELTA][b[i] + DELTA]++;
cnt[DELTA - a[i]][DELTA - b[i]]++;
}
long long ans = 0;
for (int i = 0; i <= LIMIT; i++)
for (int j = 0; j <= LIMIT; j++) {
ans = (ans + (long long) key[i][j] * cnt[i][j]) % P;
cnt[i][j + 1] = (cnt[i][j + 1] + cnt[i][j]) % P;
cnt[i + 1][j] = (cnt[i + 1][j] + cnt[i][j]) % P;
}
for (int i = 1; i <= n; i++)
ans = (ans - getc(a[i] + a[i] + b[i] + b[i], a[i] + a[i])) % P;
ans = (ans + P) % P;
ans = ans * power(2, P - 2) % P;
cout << ans << endl;
return 0;
} | codenet | -1 | 1,510 |
s796623598 | p04051 | 1,507,653,141 | cpp | Accepted | 169 | 96,640 | #include<bits/stdc++.h>
using namespace std;
#define MAXN 200005
#define MAXM 4005
#define DELTA 2000
#define LIMIT 4000
#define P 1000000007
template <typename T> void read(T &x) {
x = 0; int f = 1;
char c = getchar();
for (; !isdigit(c); c = getchar()) if (c == '-') f = -f;
for (; isdigit(c); c = getchar()) x = x * 10 + c - '0';
x *= f;
}
int a[MAXN], b[MAXN];
int cnt[MAXM][MAXM];
int key[MAXM][MAXM];
long long fac[MAXM * 2], inv[MAXM * 2];
long long power(long long x, long long y) {
if (y == 0) return 1;
long long tmp = power(x, y / 2);
if (y % 2 == 0) return tmp * tmp % P;
else return tmp * tmp % P * x % P;
}
long long getc(int x, int y) {
return fac[x] * inv[y] % P * inv[x - y] % P;
}
int main() {
int N = MAXM * 2 - 1;
fac[0] = 1;
for (int i = 1; i <= N; i++)
fac[i] = fac[i - 1] * i % P;
inv[N] = power(fac[N], P - 2);
for (int i = N - 1; i >= 0; i--)
inv[i] = inv[i + 1] * (i + 1) % P;
int n; read(n);
for (int i = 1; i <= n; i++) {
read(a[i]), read(b[i]);
key[a[i] + DELTA][b[i] + DELTA]++;
cnt[DELTA - a[i]][DELTA - b[i]]++;
}
long long ans = 0;
for (int i = 0; i <= LIMIT; i++)
for (int j = 0; j <= LIMIT; j++) {
ans = (ans + (long long) key[i][j] * cnt[i][j]) % P;
cnt[i][j + 1] = (cnt[i][j + 1] + cnt[i][j]) % P;
cnt[i + 1][j] = (cnt[i + 1][j] + cnt[i][j]) % P;
}
for (int i = 1; i <= n; i++)
ans = (ans - getc(a[i] + a[i] + b[i] + b[i], a[i] + a[i])) % P;
ans = (ans + P) % P;
ans = ans * power(2, P - 2) % P;
cout << ans << endl;
return 0;
} | codenet | -1 | 1,510 |
s744796889 | p04051 | 1,590,024,141 | cpp | Accepted | 128 | 67,072 | #include <bits/stdc++.h>
using namespace std;
typedef long long LL;
typedef pair<int, int> P;
template<typename T> inline void chkmin(T &a, const T &b) { a = a < b ? a : b; }
template<typename T> inline void chkmax(T &a, const T &b) { a = a > b ? a : b; }
const int MAXM = 4005, MAXN = 200005, MOD = 1e9 + 7;
void add(int &a, int b) { a += b - MOD, a += a >> 31 & MOD; }
void sub(int &a, int b) { a -= b, a += a >> 31 & MOD; }
int hav[MAXM][MAXM];
int aa[MAXN], bb[MAXN], f[MAXM], n;
LL fac[MAXN], inv[MAXN];
LL modpow(LL a, int b) {
LL res = 1;
for (; b; b >>= 1) {
if (b & 1) res = res * a % MOD;
a = a * a % MOD;
}
return res;
}
void init() {
int n = 2e5;
for (int i = fac[0] = 1; i <= n; i++) fac[i] = fac[i - 1] * i % MOD;
inv[n] = modpow(fac[n], MOD - 2);
for (int i = n; i > 0; i--) inv[i - 1] = inv[i] * i % MOD;
}
LL binom(int a, int b) { return fac[a] * inv[b] % MOD * inv[a - b] % MOD; }
int main() {
scanf("%d", &n);
const int M = 2000;
for (int i = 1; i <= n; i++) {
scanf("%d%d", aa + i, bb + i);
++hav[M + aa[i]][M + bb[i]];
++hav[M - aa[i]][M - bb[i]];
}
init();
int ans = 0;
for (int i = 0; i <= 4000; i++) {
f[0] += hav[i][0];
for (int j = 1; j <= 4000; j++) {
add(f[j], f[j - 1]);
if (hav[i][j]) {
if (i <= M) f[j] += hav[i][j];
else ans = (ans + (LL)f[j] * hav[i][j]) % MOD;
}
}
}
for (int i = 1; i <= n; i++)
sub(ans, binom(aa[i] + bb[i] + aa[i] + bb[i], aa[i] + aa[i]));
printf("%lld\n", (LL)ans * (MOD + 1) / 2 % MOD);
return 0;
} | codenet | -1 | 1,512 |
s025549738 | p04051 | 1,503,208,591 | cpp | Accepted | 245 | 160,640 | #include <iostream>
#include <fstream>
#include <vector>
#include <string>
#include <algorithm>
#include <set>
#include <map>
#include <cmath>
#include <cstring>
#include <ctime>
#include <unordered_map>
#include <iomanip>
using namespace std;
#define fi first
#define se second
#define pb push_back
#define all(v) (v).begin(),(v).end()
typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef pair<int,int> pii;
ll fpow(ll x, ll p, ll mod){ ll res=1; for (;p;p>>=1){ if (p&1) res=(res*x)%mod; x=(x*x)%mod;} return res;}
ll gcd(ll a, ll b){ if (!b) return a; return gcd(b,a%b); }
const int maxc=2000,mod=1000000007;
ll N,a[200100],b[200100],dp[2*maxc+10][2*maxc+10],cnt[maxc+10][maxc+10],f[4*maxc+10];
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
cin >> N;
int i,j;
for (i=1; i<=N; i++){
cin >> a[i] >> b[i];
cnt[a[i]][b[i]]++;
}
for (i=maxc; i>=-maxc; i--)
for (j=maxc; j>=-maxc; j--){
dp[i+maxc][j+maxc]=(dp[i+maxc+1][j+maxc]+dp[i+maxc][j+maxc+1])%mod;
if (i>0 && j>0) dp[i+maxc][j+maxc]=(dp[i+maxc][j+maxc]+cnt[i][j])%mod;
}
f[0]=1;
for (i=1; i<=4*maxc; i++)
f[i]=(i*f[i-1])%mod;
ll res=0;
for (i=1; i<=N; i++){
res=(res+dp[-a[i]+maxc][-b[i]+maxc])%mod;
ll val=f[2*(a[i]+b[i])]*fpow(f[2*a[i]],mod-2,mod)%mod*fpow(f[2*b[i]],mod-2,mod)%mod;
res=(res-val+mod)%mod;
}
res=res*fpow(2,mod-2,mod)%mod;
cout << res << "\n";
return 0;
}
| codenet | -1 | 1,516 |
s216288998 | p04051 | 1,570,149,203 | cpp | Accepted | 145 | 68,992 | #include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <numeric>
#include <functional>
#define LOG(FMT...) fprintf(stderr, FMT)
using namespace std;
typedef long long ll;
const int N = 200010, P = 1000000007, A = 2010;
int n;
int a[N], b[N], fac[N * 4], ifac[N * 4];
int f[A * 2][A * 2];
void add(int& x, int y) {
if ((x += y) >= P)
x -= P;
}
void sub(int& x, int y) {
if ((x -= y) < 0)
x += P;
}
int main() {
// freopen("test.in", "r", stdin);
// freopen("test.out", "w", stdout);
scanf("%d", &n);
int ma = 0, mb = 0;
for (int i = 0; i < n; ++i) {
scanf("%d%d", &a[i], &b[i]);
ma = max(ma, a[i]);
mb = max(mb, b[i]);
}
for (int i = 0; i < n; ++i)
++f[ma - a[i]][mb - b[i]];
for (int i = 0; i <= ma * 2; ++i)
for (int j = 0; j <= mb * 2; ++j) {
if (i) add(f[i][j], f[i - 1][j]);
if (j) add(f[i][j], f[i][j - 1]);
}
int ans = 0;
for (int i = 0; i < n; ++i)
add(ans, f[ma + a[i]][mb + b[i]]);
fac[0] = 1;
int K = (ma + mb) * 2;
for (int i = 1; i <= K; ++i)
fac[i] = fac[i - 1] * (ll)i % P;
ifac[1] = 1;
for (int i = 2; i <= K; ++i)
ifac[i] = -(P / i) * (ll)ifac[P % i] % P + P;
ifac[0] = 1;
for (int i = 1; i <= K; ++i)
ifac[i] = ifac[i - 1] * (ll)ifac[i] % P;
for (int i = 0; i < n; ++i)
ans = (ans + (P - fac[(a[i] + b[i]) * 2]) * (ll)ifac[a[i] * 2] % P * ifac[b[i] * 2]) % P;
if (ans & 1) ans += P;
ans >>= 1;
printf("%d\n", ans);
return 0;
}
| codenet | -1 | 1,518 |
s167694052 | p04051 | 1,519,863,453 | cpp | Accepted | 226 | 135,424 | #include <bits/stdc++.h>
#define endl '\n'
using namespace std;
template<class T, class T2> inline void chkmax(T &x, const T2 &y) { if(x < y) x = y; }
template<class T, class T2> inline void chkmin(T &x, const T2 &y) { if(x > y) x = y; }
const int MAXN = (1 << 20);
const int OFFSET = (1 << 11);
const int MAXM = (1 << 12);
const int mod = (int)1e9 + 7;
const int inv2 = (mod + 1) / 2;
int n;
int a[MAXN], b[MAXN];
void read()
{
cin >> n;
for(int i = 0; i < n; i++)
cin >> a[i] >> b[i];
}
int dp[MAXM][MAXM];
int C[MAXM][MAXM];
void solve()
{
C[0][0] = 1;
for(int i = 0; i < MAXM; i++)
for(int j = 0; j < MAXM; j++)
{
if(i) C[i][j] += C[i - 1][j];
if(C[i][j] >= mod) C[i][j] -= mod;
if(j) C[i][j] += C[i][j - 1];
if(C[i][j] >= mod) C[i][j] -= mod;
}
int answer = 0;
for(int i = 0; i < n; i++)
{
answer = answer + mod - C[2 * b[i]][2 * a[i]];
if(answer >= mod) answer -= mod;
if(answer < 0) answer += mod;
}
for(int i = 0; i < n; i++)
dp[OFFSET - b[i]][OFFSET - a[i]]++;
for(int i = 0; i < MAXM; i++)
for(int j = 0; j < MAXM; j++)
{
if(i) dp[i][j] += dp[i - 1][j];
if(dp[i][j] >= mod) dp[i][j] -= mod;
if(j) dp[i][j] += dp[i][j - 1];
if(dp[i][j] >= mod) dp[i][j] -= mod;
}
for(int i = 0; i < n; i++)
{
answer += dp[OFFSET + b[i]][OFFSET + a[i]];
if(answer >= mod) answer -= mod;
}
answer = (answer * 1ll * inv2) % mod;
cout << answer << endl;
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
read();
solve();
return 0;
}
| codenet | -1 | 1,520 |
s977715021 | p04051 | 1,522,354,702 | cpp | Accepted | 109 | 81,152 | #include <bits/stdc++.h>
#define F(i, l, r) for(int i = (l), _end_ = (int)(r); i <= _end_; ++i)
#define f(i, r, l) for(int i = (r), _end_ = (int)(l); i >= _end_; --i)
#define Set(a, v) memset(a, v, sizeof(a))
#define file(a) freopen(a".in","r",stdin),freopen(a".out","w",stdout)
using namespace std;
bool chkmin(int &a, int b) {return b < a ? a = b, 1 : 0;}
bool chkmax(int &a, int b) {return b > a ? a = b, 1 : 0;}
inline int read() {
int x = 0, fh = 1; char ch = getchar();
for (; !isdigit(ch); ch = getchar() ) if (ch == '-') fh = -1;
for (; isdigit(ch); ch = getchar() ) x = (x<<1) + (x<<3) + (ch ^ '0');
return x * fh;
}
int n;
int a[200005],b[200005];
int dp[5005][5005];
int f[100005],inv[100005];
const int mod=1e9+7;
long long qpow(long long x,long long y){
long long res=1;
while(y){
if(y&1)res=res*x%mod;
x=x*x%mod;
y>>=1;
}
return res;
}
int main () {
n=read();
F(i,1,n){
a[i]=read(),b[i]=read();
dp[2000-a[i]][2000-b[i]]++;
}
F(i,0,4000){
F(j,0,4000){
dp[i][j]=((j==0?0:dp[i][j-1])+(i==0?0:dp[i-1][j])+dp[i][j])%mod;
}
}
int ans=0;
F(i,1,n){
ans=(ans+dp[a[i]+2000][b[i]+2000])%mod;
}
f[0]=1;
F(i,1,30000)f[i]=f[i-1]*1ll*i%mod;
inv[30000]=qpow(f[30000],mod-2);
f(i,30000-1,0)inv[i]=1ll*inv[i+1]*(i+1)%mod;
// F(i,1,30000)cout<<f[i]<<" "<<inv[i]<<endl;
F(i,1,n){
ans=(ans-f[a[i]+a[i]+b[i]+b[i]]*1ll*inv[b[i]+b[i]]%mod*inv[a[i]+a[i]]%mod+mod)%mod;
}
ans=(1ll*ans*qpow(2,mod-2))%mod;
printf("%d\n",ans);
return 0;
} | codenet | -1 | 1,524 |
s879336480 | p04051 | 1,486,703,107 | cpp | Accepted | 243 | 86,272 | #include <bits/stdc++.h>
using namespace std;
const int maxV = 2000;
const int dim = maxV * 2 + 10;
const int mod = 1e9 + 7;
int n, ans;
int fact[2*dim], ifact[2*dim];
int dp[dim][dim], cnt[dim][dim];
int sum(int a, int b) {
a += b; if (a >= mod) a -= mod; return a;
}
int diff(int a, int b) {
a -= b; if (a < 0) a += mod; return a;
}
int mul(int a, int b) {
return (1LL * a * b) % mod;
}
int lgpow(int a, int b) {
int res = 1;
for (int i = 0; (1 << i) <= b; ++i) {
if (b & (1 << i))
res = mul(res, a);
a = mul(a, a);
}
return res;
}
int f(int x, int y) {
int res = fact[x+y];
res = mul(res, ifact[x]);
res = mul(res, ifact[y]);
return res;
}
int main()
{
// freopen("input","r",stdin);
// freopen("output","w",stdout);
fact[0] = ifact[0] = 1;
for (int i = 1; i <= maxV * 4; ++i)
fact[i] = mul(fact[i-1], i),
ifact[i] = mul(ifact[i-1], lgpow(i, mod - 2));
scanf("%d", &n);
for (int i = 1; i <= n; ++i) {
int a, b; scanf("%d %d", &a, &b);
ans = diff(ans, f(a + a, b + b));
dp[maxV-a][maxV-b]++;
cnt[maxV+a][maxV+b]++;
}
for (int i = 0; i <= maxV * 2; ++i)
for (int j = 0; j <= maxV * 2; ++j) {
if (i) dp[i][j] = sum(dp[i][j], dp[i-1][j]);
if (j) dp[i][j] = sum(dp[i][j], dp[i][j-1]);
if (cnt[i][j]) ans = sum(ans, mul(cnt[i][j], dp[i][j]));
}
printf("%d\n", mul(ans, lgpow(2, mod - 2)));
return 0;
}
| codenet | -1 | 1,524 |
s609870016 | p04051 | 1,573,420,729 | cpp | Accepted | 329 | 150,400 | #include<bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
typedef int ll;
typedef long long int li;
const ll MAXN=2e5+51,MOD=1e9+7;
ll cnt,offset=3000,res;
ll x[MAXN],y[MAXN],fact[MAXN>>4],finv[MAXN>>4],dp[MAXN>>5][MAXN>>5];
inline ll read()
{
register ll num=0,neg=1;
register char ch=getchar();
while(!isdigit(ch)&&ch!='-')
{
ch=getchar();
}
if(ch=='-')
{
neg=-1;
ch=getchar();
}
while(isdigit(ch))
{
num=(num<<3)+(num<<1)+(ch-'0');
ch=getchar();
}
return num*neg;
}
inline ll qpow(ll base,ll exponent)
{
ll res=1;
while(exponent)
{
if(exponent&1)
{
res=(li)res*base%MOD;
}
base=(li)base*base%MOD,exponent>>=1;
}
return res;
}
inline void setup(ll cnt)
{
fact[0]=fact[1]=finv[0]=1;
for(register int i=2;i<=cnt;i++)
{
fact[i]=(li)fact[i-1]*i%MOD;
}
finv[cnt]=qpow(fact[cnt],MOD-2);
for(register int i=cnt-1;i;i--)
{
finv[i]=(li)finv[i+1]*(i+1)%MOD;
}
}
inline ll calc(ll p)
{
return (li)fact[(x[p]+y[p])<<1]*finv[x[p]<<1]%MOD*finv[y[p]<<1]%MOD;
}
int main()
{
setup(8000),cnt=read();
for(register int i=0;i<cnt;i++)
{
dp[offset-(x[i]=read())][offset-(y[i]=read())]++;
}
for(register int i=1;i<=(offset<<1);i++)
{
for(register int j=1;j<=(offset<<1);j++)
{
dp[i][j]=(dp[i][j]+(dp[i-1][j]+dp[i][j-1])%MOD)%MOD;
}
}
for(register int i=0;i<cnt;i++)
{
res=(res+dp[offset+x[i]][offset+y[i]])%MOD;
res=(res-calc(i)+MOD)%MOD;
}
printf("%d\n",res&1?(res+MOD)>>1:res>>1);
}
| codenet | -1 | 1,525 |
s273377816 | p04051 | 1,468,777,549 | cpp | Accepted | 1,455 | 189,824 | #define _USE_MATH_DEFINES
#include <algorithm>
#include <cstdio>
#include <functional>
#include <iostream>
#include <cfloat>
#include <climits>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <time.h>
#include <vector>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<ll, int> ll_i;
typedef pair<double, int> d_i;
typedef pair<ll, ll> ll_ll;
typedef pair<double, double> d_d;
struct edge { int u, v; ll w; };
int INF = INT_MAX / 2;
ll MOD = 1000000007;
ll _MOD = 1000000009;
double EPS = 1e-10;
int main() {
int N; cin >> N;
vector<int> a(N), b(N);
vector<vector<int> > dp(4002, vector<int>(4002));
for (int i = 0; i < N; i++) {
scanf("%d%d", &a[i], &b[i]);
dp[2000 - a[i]][2000 - b[i]]++;
}
for (int y = 0; y <= 4000; y++)
for (int x = 0; x <= 4000; x++) {
dp[y + 1][x] = (dp[y + 1][x] + dp[y][x]) % MOD;
dp[y][x + 1] = (dp[y][x + 1] + dp[y][x]) % MOD;
}
int ans = 0;
for (int i = 0; i < N; i++)
ans = (ans + dp[2000 + a[i]][2000 + b[i]]) % MOD;
vector<vector<int> > C(8001, vector<int>(4001));
for (int i = 0; i <= 8000; i++) {
C[i][0] = 1;
for (int j = 1; j <= min(i, 4000); j++)
C[i][j] = (C[i - 1][j - 1] + C[i - 1][j]) % MOD;
}
for (int i = 0; i < N; i++) {
int x = C[(a[i] + b[i]) * 2][a[i] * 2];
ans = (ans - x) % MOD;
}
ans = (ll)ans * (MOD/2+1) % MOD;
cout << (ans + MOD) % MOD << endl;
}
| codenet | -1 | 1,528 |
s273377816 | p04051 | 1,468,777,549 | cpp | Accepted | 1,455 | 189,824 | #define _USE_MATH_DEFINES
#include <algorithm>
#include <cstdio>
#include <functional>
#include <iostream>
#include <cfloat>
#include <climits>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <time.h>
#include <vector>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<ll, int> ll_i;
typedef pair<double, int> d_i;
typedef pair<ll, ll> ll_ll;
typedef pair<double, double> d_d;
struct edge { int u, v; ll w; };
int INF = INT_MAX / 2;
ll MOD = 1000000007;
ll _MOD = 1000000009;
double EPS = 1e-10;
int main() {
int N; cin >> N;
vector<int> a(N), b(N);
vector<vector<int> > dp(4002, vector<int>(4002));
for (int i = 0; i < N; i++) {
scanf("%d%d", &a[i], &b[i]);
dp[2000 - a[i]][2000 - b[i]]++;
}
for (int y = 0; y <= 4000; y++)
for (int x = 0; x <= 4000; x++) {
dp[y + 1][x] = (dp[y + 1][x] + dp[y][x]) % MOD;
dp[y][x + 1] = (dp[y][x + 1] + dp[y][x]) % MOD;
}
int ans = 0;
for (int i = 0; i < N; i++)
ans = (ans + dp[2000 + a[i]][2000 + b[i]]) % MOD;
vector<vector<int> > C(8001, vector<int>(4001));
for (int i = 0; i <= 8000; i++) {
C[i][0] = 1;
for (int j = 1; j <= min(i, 4000); j++)
C[i][j] = (C[i - 1][j - 1] + C[i - 1][j]) % MOD;
}
for (int i = 0; i < N; i++) {
int x = C[(a[i] + b[i]) * 2][a[i] * 2];
ans = (ans - x) % MOD;
}
ans = (ll)ans * (MOD/2+1) % MOD;
cout << (ans + MOD) % MOD << endl;
}
| codenet | -1 | 1,528 |
s949692535 | p04051 | 1,576,062,196 | cpp | Accepted | 114 | 64,512 | //#include<bits/stdc++.h>
#include<iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <set>
#include <queue>
#include <deque>
#include <map>
#include <stack>
#include<bitset>
#include<list>
#include<cassert>
#include<numeric>
using namespace std;
const int N = 200005;
const int mod = 1000000007;
int n,F[4005][4005],fac[8005],inv[8005],A[N],B[N],ans;
int read()
{
int ret = 0;
int f = 1;
char ch = getchar();
while(ch < '0'||ch > '9')
{
if (ch == '-')
{
f =- f;
ch = getchar();
}
}
while (ch >= '0'&&ch <= '9')
{
ret = ret * 10 + ch - '0';
ch = getchar();
}
return ret * f;
}
inline int QP(int a,int b)
{
int ret = 1;
int w = a;
while(b)
{
if(b & 1)
ret = (long long)ret * w % mod;
w = (long long)w * w % mod;
b >>= 1;
}
return ret;
}
int C(int n,int m)
{
return (long long)fac[n] * inv[m] % mod * inv[n - m] % mod;
}
int main()
{
n = read();
fac[0]=1;
for(int i=1; i<=8000;i++)
{
fac[i] = (long long)fac[i - 1] * i % mod;
inv[i] = QP(fac[i], mod - 2);
}
for(int i = 1; i <= n; i++)
{
A[i] = read();
B[i] = read();
F[2000 - A[i]][2000 - B[i]]++;
}
for (int i = 0;i <= 4000; i++)
{
for (int j = 0;j <= 4000; j++)
{
F[i][j] = ((long long)F[i][j] + (j ? F[i][j - 1] : 0) + (i ? F[i - 1][j] : 0)) % mod;
}
}
for (int i = 1; i <= n;i++)
{
ans = (ans + F[2000 + A[i]][2000 + B[i]]) % mod;
ans = (ans - C(A[i] + B[i] + A[i] + B[i], A[i] + A[i]) + mod)%mod;
}
ans = (long long)ans * QP(2,mod - 2) % mod;
cout << ans << endl;
}
| codenet | -1 | 1,529 |
s552985544 | p04051 | 1,586,214,925 | cpp | Accepted | 268 | 180,736 | #include<iostream>
#include<cstdio>
#include<algorithm>
#include<cassert>
#include<cmath>
#include<vector>
#include<map>
#include<set>
#include<string>
#include<queue>
#include<stack>
using namespace std;
#define MOD 1000000007
#define MOD2 998244353
#define INF ((1<<30)-1)
#define LINF (1LL<<60)
#define EPS (1e-10)
typedef long long Int;
typedef pair<Int, Int> P;
Int fact[1100000];
Int revfact[1100000];
Int rev[1100000];
void init(){
Int m = MOD;
fact[0] = 1;
revfact[0] = 1;
rev[0] = 0;
rev[1] = 1;
for(int i = 1;i < 1100000;i++){
fact[i] = fact[i-1] * i % m;
if(i>1)rev[i] = MOD / i * (MOD-rev[MOD % i]) % MOD;
revfact[i] = revfact[i-1] * rev[i] % MOD;
}
}
Int nCk(Int n, Int k){
if(n < k)return 0;
return fact[n] * revfact[n-k] % MOD * revfact[k] % MOD;
}
Int n, a[220000], b[220000];
Int dp_[4400][4400];
Int &dp(int x, int y){
return dp_[x+2200][y+2200];
}
int main(){
init();
cin >> n;
for(int i = 0;i < n;i++){
cin >> a[i] >> b[i];
dp(-a[i], -b[i])++;
}
for(int i = 0;i < 4400;i++){
for(int j = 0;j < 4400;j++){
if(i)dp_[i][j] += dp_[i-1][j];
if(j)dp_[i][j] += dp_[i][j-1];
dp_[i][j] %= MOD;
}
}
Int ans = 0;
for(int i = 0;i < n;i++){
ans += dp(a[i], b[i]);
ans -= nCk(2*(a[i] + b[i]), 2*a[i]);
ans %= MOD;
}
if(ans < 0)ans += MOD;
if(ans % 2 == 1)ans += MOD;
ans /= 2;
cout << ans << endl;
return 0;
} | codenet | -1 | 1,532 |
s552985544 | p04051 | 1,586,214,925 | cpp | Accepted | 268 | 180,736 | #include<iostream>
#include<cstdio>
#include<algorithm>
#include<cassert>
#include<cmath>
#include<vector>
#include<map>
#include<set>
#include<string>
#include<queue>
#include<stack>
using namespace std;
#define MOD 1000000007
#define MOD2 998244353
#define INF ((1<<30)-1)
#define LINF (1LL<<60)
#define EPS (1e-10)
typedef long long Int;
typedef pair<Int, Int> P;
Int fact[1100000];
Int revfact[1100000];
Int rev[1100000];
void init(){
Int m = MOD;
fact[0] = 1;
revfact[0] = 1;
rev[0] = 0;
rev[1] = 1;
for(int i = 1;i < 1100000;i++){
fact[i] = fact[i-1] * i % m;
if(i>1)rev[i] = MOD / i * (MOD-rev[MOD % i]) % MOD;
revfact[i] = revfact[i-1] * rev[i] % MOD;
}
}
Int nCk(Int n, Int k){
if(n < k)return 0;
return fact[n] * revfact[n-k] % MOD * revfact[k] % MOD;
}
Int n, a[220000], b[220000];
Int dp_[4400][4400];
Int &dp(int x, int y){
return dp_[x+2200][y+2200];
}
int main(){
init();
cin >> n;
for(int i = 0;i < n;i++){
cin >> a[i] >> b[i];
dp(-a[i], -b[i])++;
}
for(int i = 0;i < 4400;i++){
for(int j = 0;j < 4400;j++){
if(i)dp_[i][j] += dp_[i-1][j];
if(j)dp_[i][j] += dp_[i][j-1];
dp_[i][j] %= MOD;
}
}
Int ans = 0;
for(int i = 0;i < n;i++){
ans += dp(a[i], b[i]);
ans -= nCk(2*(a[i] + b[i]), 2*a[i]);
ans %= MOD;
}
if(ans < 0)ans += MOD;
if(ans % 2 == 1)ans += MOD;
ans /= 2;
cout << ans << endl;
return 0;
} | codenet | -1 | 1,532 |