Cod sursa(job #2330582)

Utilizator ionanghelinaIonut Anghelina ionanghelina Data 28 ianuarie 2019 17:03:10
Problema Dirichlet Scor 88
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.73 kb
#include<bits/stdc++.h>
using namespace std;

const int mod=9999991;



inline long long fastexp(long long a,long long b)
{
    long long res=1LL;
    while(b)
    {
        if(b&1)
        {
            res=(res*a)%mod;
            b--;
        }
            else
        {
            a=(a*a)%mod;
            b>>=1LL;
        }
    }

    return res;
}



long long n;

int main()
{
    freopen("dirichlet.in","r",stdin);
    freopen("dirichlet.out","w",stdout);

    scanf("%lld",&n);

    long long sol=1LL;

    for(long long i=n+2;i<=2LL*n;i++)
        sol=(sol*i)%mod;

    for(long long i=1;i<=n;i++)
        sol=(sol*fastexp(i,mod-2LL))%mod;





    printf("%lld\n",sol);
    return 0;
}