Submission #777268

#	Time	Username	Problem	Language	Result	Execution time	Memory
777268		yeyso	Asceticism (JOI18_asceticism)	C++14	49 / 100	131 ms	262144 KiB

asceticism

#include <bits/stdc++.h>
using namespace std;
int main(){
    long long n, k; cin >> n >> k;
    k = n - k;
    long long mod = 1e9 + 7;
    vector<vector<long long>> dp(n+1, vector<long long>(k+1, 0));
    for(long long i = 0; i < n+1; i ++){
        dp[i][0] = 1;
        if(i > 0) for(long long j = 1; j < k+1; j ++) dp[i][j] = ((dp[i-1][j-1] * (i - j)) % mod + (dp[i-1][j] * (j + 1)) % mod) % mod;
    }
    cout << dp[n][k];
}

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