/* >>~~ UVa Online Judge ACM Problem Solution ~~<< ID: 10007 Name: Count the Trees Problem: https://onlinejudge.org/external/100/10007.pdf Language: C++ Author: Arash Shakery Email: arash.shakery@gmail.com */ #include using namespace std; class BigInt { typedef int CellType; const static int CellSize = sizeof(CellType); const static int MAX_C = 10000; const static int MAX_D = 4; CellType *cells; int capacity, size, sign; int sgn(int x) { return x<0 ? -1 : x>0 ? 1 : 0; } int countDigits(int x) { if (!x) return 0; if (x < 0) x = -x; return floor(log10(x)) + 1; } void init() { sign = size = 0; cells = new CellType[capacity = 4]; memset(cells, 0, 4*CellSize); } int setSize(int sz, bool cp = true) { if (sz > capacity) { CellType* ncells = new CellType[capacity = sz + 16]; if (cp && size) memcpy(ncells, cells, size*CellSize); if (cells) delete [] cells; cells = ncells; } if (!cp) memset(cells, 0, capacity*CellSize); else memset(cells+sz, 0, (capacity-sz)*CellSize); return size = sz; } BigInt& autoSize() { while (size>0 && !cells[size-1]) size--; if (!size) sign=0; return *this; } // --------------------------------------------------------------------- public: BigInt() { init(); } BigInt(int x) { init(); setTo(x); } BigInt(const char s[]) { while (s[0]==' ' || s[0]=='\n' || s[0]=='\t') s++; sign = 1; if (s[0] == '+') s++; if (s[0] == '-') { sign=-1; s++; } while (s[0]=='0') s++; if (!s[0]) { init(); return; } int len = strlen(s); size = (len+3)/MAX_D; cells = new CellType[capacity = size+16]; for (int i=len-1; i>=0; i-=MAX_D) { int rc = 0; for (int k=i-MAX_D+1; k<=i; k++) { if (k<0 || s[k]=='-' || s[k]=='+') continue; rc = rc*10 + s[k] - '0'; } cells[(len-i-1) / MAX_D] = rc; } for (int i=size; i= 0) delete [] cells; } int getSize() { return size; } int getCell(int i) { return cells[i]; } bool isZero() { return !sign; } BigInt& setOne() { sign=size=cells[0]=1; return *this; } BigInt& setTo(int x) { sign = sgn(x); x*=sign; for (size=0; x; size++) { cells[size] = x % MAX_C; x /= MAX_C; } return *this; } // --------------------------------------------------------------------- private: bool numLess(const BigInt &o) const { if (size != o.size) return size < o.size; for (int i=size-1; i>=0; i--) if (cells[i] != o.cells[i]) return cells[i] < o.cells[i]; return false; } bool numEq(const BigInt &o) const { if (size!=o.size) return false; for (int i=size-1; i>=0; i--) if (cells[i] != o.cells[i]) return false; return true; } public: bool operator < (const BigInt &o) const { return sign==o.sign ? (sign>0 ? numLess(o) : o.numLess(*this)) : sign < o.sign; } bool operator == (const BigInt &o) const { return sign==o.sign && numEq(o); } bool operator != (const BigInt &o) const { return !(*this == o); } bool operator <= (const BigInt &o) const { return !(o < *this); } bool operator > (const BigInt &o) const { return (o < *this); } bool operator >= (const BigInt &o) const { return !(*this < o); } // --------------------------------------------------------------------- BigInt& operator=(const BigInt& o) { if ((sign = o.sign)) { setSize(o.size, 0); memcpy(cells, o.cells, o.size*CellSize); } else size=0; return *this; } BigInt& operator+= (BigInt o) { if (!o.sign) return *this; if (!sign) sign = o.sign; if (sign != o.sign) { o.sign *= -1; operator-=(o); o.sign *= -1; return *this; } int osz = size; setSize(max(size, o.size)+1); for (int i=osz; i= MAX_C) { cells[i] -= MAX_C; ++cells[i+1]; } } return autoSize(); } BigInt& operator+= (int x) { return *this += *new BigInt(x); } //TODO: optimize BigInt operator+ (int x) const { return *new BigInt(*this) += x; } BigInt operator+ (BigInt& o) const { return *new BigInt(*this) += o; } // --------------------------------------------------------------------- BigInt& operator-= (BigInt& o) { if (!o.sign) return *this; if (!sign) sign = -o.sign; if (sign != o.sign) { o.sign *= -1; operator+=(o); o.sign *= -1; return *this; } if (*this == o) { sign = size = 0; return *this; } if (!o.numLess(*this)) return *this = -(o - *this); for (int i=0; i 10000) { return *this *= BigInt(x); } sign *= sgn(x); if (!sign) { size = 0; return *this; } if (x<0) x = -x; int cr = 0; for (int i=0; i < size; i++) { cells[i] = cells[i] * x + cr; cr = cells[i] / MAX_C; cells[i] %= MAX_C; } if (cr) { int ex = (countDigits(cr)+MAX_D-1)/MAX_D, sz=size; setSize(size + ex); size = sz; for (; cr; cr /= MAX_C) cells[size++] = cr % MAX_C; } return autoSize(); } BigInt operator* (const BigInt &o) const { if (sign*o.sign == 0) return *new BigInt(0); if (o.size == 1) return *new BigInt(*this) *= o.cells[0]; BigInt r(sign*o.sign); r.setSize(size + o.size + 1, 0); for (int i=0; i=0; --i) { t = t*MAX_C + cells[i]; cells[i] = t / den; t -= (long long) cells[i] * den; } return autoSize(); } BigInt operator/ (int den) const { return *new BigInt(*this) /= den; } int operator% (int den) const { int r = 0; for (int i = size-1; i>=0; --i) r = (r * MAX_C + cells[i]) % den; return r; } // --------------------------------------------------------------------- friend std::ostream& operator<< (std::ostream& stream, const BigInt& bs) { if (!bs.sign) stream << 0; else { if (bs.sign < 0) stream << '-'; stream << bs.cells[bs.size-1]; for (int i=bs.size-2; i>=0; i--) stream << setfill('0') << setw(MAX_D) << bs.cells[i]; } return stream; } }; BigInt operator*(int m, BigInt &n) { return n * m; } BigInt operator+(int m, BigInt &n) { return n + m; } BigInt operator-(int m, BigInt &n) { return -n + m; } // ---------------------------------------------------------------------------------- int main() { ios_base::sync_with_stdio(0);cin.tie(0); BigInt F[313]; F[0].setOne(); F[1].setOne(); for (int i=2; i<301; ++i) F[i] = F[i-1] * i; BigInt C[313]; C[0].setOne(); for (int i=1; i<313; ++i) { C[i] = C[i-1]; C[i] *= 4*i-2; C[i] /= i+1; } int n; while (cin >> n && n) cout << C[n] * F[n] << endl; }