Submission #752601

#	Time	Username	Problem	Language	Result	Execution time	Memory
752601		bgnbvnbv	Asceticism (JOI18_asceticism)	C++14	49 / 100	125 ms	94476 KiB

asceticism

#include<bits/stdc++.h>
#define TASKNAME "codeforce"
#define pb push_back
#define pli pair<int,int>
#define fi first
#define se second
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL);
using namespace std;
using ll=long long;
const ll maxN=2e5;
const ll inf=1e18;
const ll mod=1e9+7;
ll dp[3005][3005],n,k;
void solve()
{
    cin >> n >> k;
    dp[1][0]=1;
    for(int i=1;i<n;i++)
    {
        for(int j=0;j<=i-1;j++)
        {
            dp[i][j]%=mod;
            dp[i+1][j+1]+=dp[i][j];
            dp[i+1][j]+=dp[i][j];
            dp[i+1][j]+=j*dp[i][j]%mod;
            dp[i+1][j+1]+=(i-1-j)*dp[i][j]%mod;
        }
    }
    cout << dp[n][k-1]%mod;
}
int main()
{
    fastio
    //freopen(TASKNAME".INP","r",stdin);
    //freopen(TASKNAME".OUT","w",stdout);
    solve();
}

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