Submission #796359

#	Time	Username	Problem	Language	Result	Execution time	Memory
796359		anton	Zapina (COCI20_zapina)	C++17	110 / 110	134 ms	3144 KiB

zapina

#include<bits/stdc++.h>

using namespace std;
#define int long long

const int mod = 1e9 +7;
const int MAX_N = 350;

int n, nb_c[MAX_N][MAX_N+1], dp[MAX_N][MAX_N+1];
int C[MAX_N+1][MAX_N];

int expo(int a, int b){
    if(b==0){
        return 1;
    }
    if(b%2==1){
        return (a*expo(a, b-1))%mod;
    }
    else{
        return (expo(a, b/2)*expo(a, b/2))%mod;
    }
}


signed main(){
    cin>>n;
    C[0][0] =1;
    C[1][0] = 1;
    C[1][1] = 1;
    for(int i = 2; i<=n; i++){
        for(int j =0; j<=n; j++){
            C[i][j] = C[i-1][j];
            if(j>0){
                C[i][j] = (C[i][j]+ C[i-1][j-1])%mod;
            }
        }
        cout<<endl;
    }
    
    for(int i = n-1; i>=0; i--){
        for(int j = 0; j<=n; j++){
            nb_c[i][j] = expo((n-i), j);
        }
    }

    for(int i = n-1; i>=0; i--){
        for(int j = 0; j<=n; j++){
            int cost = i+1;
            if(i==n-1){
                if(j==cost){
                    dp[i][j] = 1;
                }
                else{
                    dp[i][j] = 0;
                }
            }
            else{
                for(int k = 0; k<=j; k++){
                    if(k!=cost){
                        dp[i][j] = (dp[i][j]+ (dp[i+1][j-k] * C[j][k])%mod)%mod;
                    }
                }
                if(j>=cost){
                    dp[i][j] = (dp[i][j]+ (nb_c[i+1][j-cost] * C[j][cost])%mod)%mod;
                }
            }

        }
    }

    cout<<dp[0][n]<<endl;
}

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