test/yukicoder/yuki117.test.cpp

View this file on GitHub
Last update: 2023-02-25 23:57:16+09:00
Problem: https://yukicoder.me/problems/no/117

Depends on

Code

#define PROBLEM "https://yukicoder.me/problems/no/117"
#include <bits/stdc++.h>
using namespace std;
#include "../../modint/modint.hpp"
#include "../../math/binom.hpp"

using mint = ModInt<1000000007>;

int main() {
    int T;
    scanf("%d\n", &T);
    Binomial<mint> binom;
    while(T--) {
        char t;
        int N, K;
        scanf("%c(%d,%d)\n", &t, &N, &K);
        if(t == 'C') {
            printf("%u\n", binom.binom(N, K).val());
        } else if(t == 'P') {
            printf("%u\n", binom.perm(N, K).val());
        } else if(t == 'H') {
            printf("%u\n", binom.hom(N, K).val());
        }
    }
}

#line 1 "test/yukicoder/yuki117.test.cpp"
#define PROBLEM "https://yukicoder.me/problems/no/117"
#include <bits/stdc++.h>
using namespace std;
#line 2 "modint/modint.hpp"

#line 6 "modint/modint.hpp"

template <int mod> class ModInt {
  public:
    ModInt() : x(0) {}
    ModInt(long long y)
        : x(y >= 0 ? y % umod() : (umod() - (-y) % umod()) % umod()) {}
    unsigned int val() const { return x; }
    ModInt &operator+=(const ModInt &p) {
        if((x += p.x) >= umod()) x -= umod();
        return *this;
    }
    ModInt &operator-=(const ModInt &p) {
        if((x += umod() - p.x) >= umod()) x -= umod();
        return *this;
    }
    ModInt &operator*=(const ModInt &p) {
        x = (unsigned int)(1ULL * x * p.x % umod());
        return *this;
    }
    ModInt &operator/=(const ModInt &p) {
        *this *= p.inv();
        return *this;
    }
    ModInt operator-() const { return ModInt(-(long long)x); }
    ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }
    ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }
    ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }
    ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }
    bool operator==(const ModInt &p) const { return x == p.x; }
    bool operator!=(const ModInt &p) const { return x != p.x; }
    ModInt inv() const {
        long long a = x, b = mod, u = 1, v = 0, t;
        while(b > 0) {
            t = a / b;
            std::swap(a -= t * b, b);
            std::swap(u -= t * v, v);
        }
        return ModInt(u);
    }
    ModInt pow(unsigned long long n) const {
        ModInt ret(1), mul(x);
        while(n > 0) {
            if(n & 1) ret *= mul;
            mul *= mul;
            n >>= 1;
        }
        return ret;
    }
    friend std::ostream &operator<<(std::ostream &os, const ModInt &p) {
        return os << p.x;
    }
    friend std::istream &operator>>(std::istream &is, ModInt &a) {
        long long t;
        is >> t;
        a = ModInt<mod>(t);
        return (is);
    }
    static constexpr int get_mod() { return mod; }

  private:
    unsigned int x;
    static constexpr unsigned int umod() { return mod; }
};
#line 2 "math/binom.hpp"

#line 6 "math/binom.hpp"

template <class mint> class Binomial {
  public:
    explicit Binomial(): Binomial(1) {}
    explicit Binomial(int MAX) : f(MAX, mint(1)), f_inv(MAX, mint(1)) {
        for(int i = 1; i < MAX; i++) f[i] = f[i-1] * mint(i);
        f_inv[MAX - 1] = f[MAX - 1].inv();
        for(int i = MAX - 2; i >= 1; i--) {
            f_inv[i] = f_inv[i + 1] * mint(i + 1);
        } 
    }
    void extend() {
        int n = (int)f.size();
        f.resize(n * 2);
        f_inv.resize(n * 2);
        for(int i = n; i < n * 2; i++) f[i] = f[i - 1] * mint(i);
        f_inv[n * 2 - 1] = f[n * 2 - 1].inv();
        for(int i = n * 2 - 2; i >= n; i--) {
            f_inv[i] = f_inv[i + 1] * mint(i + 1);
        }
    }
    mint fac(int n) {
        if(n < 0) return mint(0);
        while(n >= (int)f.size()) extend();
        return f[n];
    }
    mint fac_inv(int n) {
        if(n < 0) return mint(0);
        while(n >= (int)f_inv.size()) extend();
        return f_inv[n];
    }
    mint inv(int n) {
        if(n < 0) return -mint(-n);
        assert(n != 0);
        while(n >= (int)f_inv.size()) extend();
        return (f_inv[n] * f[n - 1]);
    }
    mint binom(int n, int k) {
        if(n < k || n < 0 || k < 0) return mint(0);
        return (fac(n) * fac_inv(k) * fac_inv(n - k));
    }
    mint binom_naive(long long n, long long k) {
        if(n < k || n < 0 || k < 0) return mint(0);
        mint res(1);
        k = std::min(k, n - k);
        for(int i = 0; i < k; i++) res *= inv(i + 1) * mint(n - i);
        return res;
    }
    mint perm(int n, int k) {
        if(n < k || n < 0 || k < 0) return mint(0);
        return (fac(n) * fac_inv(n - k));
    }
    mint hom(int n, int k) {
        if(n < 0 || k < 0) return mint(0);
        return (k == 0 ? mint(1) : binom(n + k - 1, k));
    }

  private:
    std::vector<mint> f, f_inv;
};
#line 6 "test/yukicoder/yuki117.test.cpp"

using mint = ModInt<1000000007>;

int main() {
    int T;
    scanf("%d\n", &T);
    Binomial<mint> binom;
    while(T--) {
        char t;
        int N, K;
        scanf("%c(%d,%d)\n", &t, &N, &K);
        if(t == 'C') {
            printf("%u\n", binom.binom(N, K).val());
        } else if(t == 'P') {
            printf("%u\n", binom.perm(N, K).val());
        } else if(t == 'H') {
            printf("%u\n", binom.hom(N, K).val());
        }
    }
}