Submission #933772

#	Time	Username	Problem	Language	Result	Execution time	Memory
933772		alexander707070	Asceticism (JOI18_asceticism)	C++14	49 / 100	98 ms	164436 KiB

asceticism

#include<bits/stdc++.h>
#define MAXN 3007
using namespace std;

const long long mod=1e9+7;

int n,k,nn,kk;
long long dp[MAXN][MAXN];
bool li[MAXN][MAXN];

long long ff(int n,int k){
    if(n==nn and k==kk)return 1;
    else if(n==nn)return 0;

    if(li[n][k])return dp[n][k];
    li[n][k]=true;

    dp[n][k]=(long long) ff(n+1,k)*k+ff(n+1,k+1)*(n+1-k);
    dp[n][k]%=mod;

    return dp[n][k];
}

int main(){

    cin>>n>>k;
    nn=n; kk=k;

    cout<<ff(1,1)<<"\n";

    return 0;
}

• Subtask 1: 4 / 4
• Subtask 2: 20 / 20
• Subtask 3: 25 / 25
• Subtask 4: 0 / 51