| # | Time | Username | Problem | Language | Result | Execution time | Memory | 
|---|---|---|---|---|---|---|---|
| 796843 | raphaelp | Zapina (COCI20_zapina) | C++14 | 0 ms | 0 KiB | 
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include<bits/stdc++.h>
using namespace std;
int main()
{
    long long N;
    cin>>N;
    long long tot=1;
    for(int i=0; i<N; i++)
    {
        tot*=N;
        tot= tot%1000000007;
    }
    vector<vector<long long>> tab (N+1, vector<long long> (N+1,0));
    tab[1][0]=1;
    for (long long i=1; i<N; i++)
    {
        for (long long j=0; j<=N; j++)
        {
            if (tab[i][j]==0) break;
            long long mult=1;
            for (long long p=0; p<=min(i,N-j); p++)
            {
                tab[i+1][j+p]+=tab[i][j]*mult;
                tab[i+1][j+p]=tab[i+1][j+p]%1000000007;
                mult*=N-j-p;
                mult=mult%1000000007;
            }
        }
    }
    tot-=tab[N][N];
    tot=tot%1000000007;
    cout<<tot;
}
