Submission #1283826

#	Time	Username	Problem	Language	Result	Execution time	Memory
1283826		aren_dance	Zapina (COCI20_zapina)	C++20	55 / 110	1096 ms	580 KiB

zapina

#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int mod=1e9+7;
const int N=351;
ll dp[N][N];
ll bpow(ll x,ll y){
    if(y==0){
        return 1;
    }
    ll g=bpow(x,y/2);
    g*=g;
    g%=mod;
    if(y%2==0){
        return g;
    }
    g*=x;
    g%=mod;
    return g;
}
ll inverse(ll x){
    return bpow(x,mod-2);
}
ll c(ll x,ll y){
    ll fx=1;
    ll fy=1;
    for(int i=1;i<=x;++i){
        fx*=i;
        fx%=mod;
    }
    for(int i=1;i<=y;++i){
        fy*=i;
        fy%=mod;
    }
    for(int i=1;i<=(x-y);++i){
        fy*=i;
        fy%=mod;
    }
    ll u=fx*inverse(fy);
    u%=mod;
    return u;
}
int main(){
    int n;
    cin>>n;
    for(int i=1;i<=n;++i){
        for(int j=1;j<=n;++j){
            for(int k=0;k<=j;++k){
                if(k==i){
                    dp[i][j]+=(bpow(i-1,j-k)*c(j,k));
                    dp[i][j]%=mod;
                    continue;
                }
                dp[i][j]+=(dp[i-1][j-k]*c(j,k));
                dp[i][j]%=mod;
            }
        }
    }
    cout<<dp[n][n];
    return 0;
}

• Subtask 1: 22 / 22
• Subtask 2: 33 / 33
• Subtask 3: 0 / 55