結果
問題 | No.1259 スイッチ |
ユーザー |
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提出日時 | 2020-10-16 23:23:12 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 546 ms / 2,000 ms |
コード長 | 1,852 bytes |
コンパイル時間 | 636 ms |
コンパイル使用メモリ | 70,404 KB |
最終ジャッジ日時 | 2025-01-15 09:46:52 |
ジャッジサーバーID (参考情報) |
judge5 / judge5 |
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ファイルパターン | 結果 |
---|---|
other | AC * 61 |
ソースコード
#include <iostream>template<class T, T MOD>class Modint{T val;public:Modint(T val = 0) : val(val % MOD + (val >= 0 ? 0 : MOD)) {}operator T(){ return val; }Modint &operator+=(const Modint &a){ val += a.val; if(val >= MOD) val -= MOD; return *this; }Modint &operator-=(const Modint &a){ val -= a.val; if(val < 0) val += MOD; return *this; }Modint &operator*=(const Modint &a){ val = val * a.val % MOD; return *this; }void inverse(){T x[2]={MOD,val},a[2]={0,1};int i;for(i=0;x[!i];i^=1){a[i]-=x[i]/x[!i]*a[!i];x[i]=x[i]%x[!i];}if(!i)a[i]+= MOD;val=a[i];}Modint &operator/=(Modint a){ a.inverse(); return *this *= a; }friend Modint modpow(Modint a, int n){ Modint ret(1); while(n){ if(n & 1) ret *= a; a *= a; n >>= 1; } return ret; }friend Modint operator+(Modint a, const Modint &b){ return a += b; }friend Modint operator-(Modint a, const Modint &b){ return a -= b; }friend Modint operator*(Modint a, const Modint &b){ return a *= b; }friend Modint operator/(Modint a, const Modint &b){ return a /= b; }friend std::ostream &operator<<(std::ostream &os, const Modint &a){ return os << a.val; }};using lint = long long;using Mint = Modint<long long, 1000000007>;int main(){lint n, k, m;std::cin >> n >> k >> m;if(m == 1){Mint x = modpow(Mint(n), n - 1);Mint y = 1;Mint ans = 0;for(int i = 1; i <= n; ++i){if(k % i == 0){ans += x * y;}x /= Mint(n);y *= Mint(n - i);}std::cout << ans << std::endl;}else{Mint x = modpow(Mint(n), n - 2);Mint y = 1;Mint ans = 0;for(int i = 1; i <= n - 1; ++i){ans += x * y * Mint(i);y *= Mint(n - i - 1);x /= Mint(n);}x = modpow(Mint(n), n - 2);y = 1;for(int i = 2; i <= n; ++i){if(k % i != 0){ans += x * y;}x /= Mint(n);y *= Mint(n - i);}std::cout << ans << std::endl;}}