結果

問題 No.117 組み合わせの数
ユーザー emthrm
提出日時 2019-10-25 15:43:34
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 147 ms / 5,000 ms
コード長 4,736 bytes
コンパイル時間 929 ms
コンパイル使用メモリ 86,564 KB
最終ジャッジ日時 2025-01-08 00:57:13
ジャッジサーバーID
（参考情報） 		judge1 / judge2
このコードへのチャレンジ
（要ログイン）
ファイルパターン 結果
other AC * 1
権限があれば一括ダウンロードができます

ソースコード

diff # 

#include <algorithm>
// #include <cassert>
#include <iostream>
#include <iomanip>
#include <utility>
#include <vector>
using namespace std;

#define FOR(i,m,n) for(int i=(m);i<(n);++i)

const int MOD = 1000000007; // 998244353;

struct IOSetup {
  IOSetup() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    cout << fixed << setprecision(20);
    cerr << fixed << setprecision(10);
  }
} iosetup;
/*-------------------------------------------------*/
long long mod_inv(long long a, int mod = MOD) {
  a %= mod;
  if (__gcd(a, static_cast<long long>(mod)) != 1) return -1;
  long long b = mod, x = 1, y = 0;
  while (b > 0) {
    long long tmp = a / b;
    a -= tmp * b;
    swap(a, b);
    x -= tmp * y;
    swap(x, y);
  }
  x %= mod;
  if (x < 0) x += mod;
  return x;
}

struct nCk {
  int val, mod;
  vector<long long> fact, fact_inv;

  nCk(int val = 10000000, int mod = MOD) : val(val), mod(mod), fact(val + 1), fact_inv(val + 1) {
    fact[0] = 1;
    FOR(i, 1, val + 1) fact[i] = fact[i - 1] * i % mod;
    fact_inv[val] = mod_inv(fact[val], mod);
    for (int i = val; i > 0; --i) fact_inv[i - 1] = fact_inv[i] * i % mod;
  }

  long long query(int n, int k) {
    if (n < 0 || n < k || k < 0) return 0;
    // assert(n <= val && k <= val);
    return fact[n] * fact_inv[k] % mod * fact_inv[n - k] % mod;
  }
};

int mod = MOD;
struct ModInt {
  unsigned val;
  ModInt(): val(0) {}
  ModInt(long long x) : val(x >= 0 ? x % mod : x % mod + mod) {}
  ModInt pow(long long exponent) {
    ModInt tmp = *this, res = 1;
    while (exponent > 0) {
      if (exponent & 1) res *= tmp;
      tmp *= tmp;
      exponent >>= 1;
    }
    return res;
  }
  ModInt &operator+=(const ModInt &rhs) { if((val += rhs.val) >= mod) val -= mod; return *this; }
  ModInt &operator-=(const ModInt &rhs) { if((val += mod - rhs.val) >= mod) val -= mod; return *this; }
  ModInt &operator*=(const ModInt &rhs) { val = static_cast<unsigned long long>(val) * rhs.val % mod; return *this; }
  ModInt &operator/=(const ModInt &rhs) { return *this *= rhs.inv(); }
  bool operator==(const ModInt &rhs) const { return val == rhs.val; }
  bool operator!=(const ModInt &rhs) const { return val != rhs.val; }
  bool operator<(const ModInt &rhs) const { return val < rhs.val; }
  bool operator<=(const ModInt &rhs) const { return val <= rhs.val; }
  bool operator>(const ModInt &rhs) const { return val > rhs.val; }
  bool operator>=(const ModInt &rhs) const { return val >= rhs.val; }
  ModInt operator-() const { return ModInt(val ? mod - val : 0); }
  ModInt operator+(const ModInt &rhs) const { return ModInt(*this) += rhs; }
  ModInt operator-(const ModInt &rhs) const { return ModInt(*this) -= rhs; }
  ModInt operator*(const ModInt &rhs) const { return ModInt(*this) *= rhs; }
  ModInt operator/(const ModInt &rhs) const { return ModInt(*this) /= rhs; }
  friend ostream &operator<<(ostream &os, const ModInt &rhs) { return os << rhs.val; }
  friend istream &operator>>(istream &is, ModInt &rhs) { long long x; is >> x; rhs = ModInt(x); return is; }
private:
  ModInt inv() const {
    // if (__gcd(val, mod) != 1) assert(false);
    unsigned a = val, b = mod; int x = 1, y = 0;
    while (b) {
      unsigned tmp = a / b;
      swap(a -= tmp * b, b);
      swap(x -= tmp * y, y);
    }
    return ModInt(x);
  }
};
int abs(const ModInt &x) { return x.val; }
struct Combinatorics {
  int val;
  vector<ModInt> fact, fact_inv, inv;
  Combinatorics(int val = 10000000) : val(val), fact(val + 1), fact_inv(val + 1), inv(val + 1) {
    fact[0] = 1;
    FOR(i, 1, val + 1) fact[i] = fact[i - 1] * i;
    fact_inv[val] = ModInt(1) / fact[val];
    for (int i = val; i > 0; --i) fact_inv[i - 1] = fact_inv[i] * i;
    FOR(i, 1, val + 1) inv[i] = fact[i - 1] * fact_inv[i];
  }
  ModInt nCk(int n, int k) {
    if (n < 0 || n < k || k < 0) return ModInt(0);
    // assert(n <= val && k <= val);
    return fact[n] * fact_inv[k] * fact_inv[n - k];
  }
  ModInt nPk(int n, int k) {
    if (n < 0 || n < k || k < 0) return ModInt(0);
    // assert(n <= val);
    return fact[n] * fact_inv[n - k];
  }
  ModInt nHk(int n, int k) {
    if (n < 0 || k < 0) return ModInt(0);
    return (k == 0 ? ModInt(1) : nCk(n + k - 1, k));
  }
};

int main() {
  Combinatorics com(1999999);
  nCk nck(1000000);
  int t; cin >> t;
  while (t--) {
    string s; cin >> s;
    string n = "";
    int idx = 2;
    for (; ; ++idx) {
      char c = s[idx];
      if (c == ',') break;
      n += c;
    }
    string k = s.substr(idx + 1);
    if (s[0] == 'C') {
      cout << nck.query(stoi(n), stoi(k));
    } else if (s[0] == 'P') {
      cout << com.nPk(stoi(n), stoi(k));
    } else {
      cout << com.nHk(stoi(n), stoi(k));
    }
    cout << '\n';
  }
  return 0;
}
0