結果

問題 No.1259 スイッチ
ユーザー 57tggx57tggx
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
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 #
プレゼンテーションモードにする

#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;
}
}
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