Cod sursa(job #2972901)

Utilizator MilitaruMihaiMihaiMIlitaru MilitaruMihai Data 30 ianuarie 2023 16:43:23
Problema Dirichlet Scor 8
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.64 kb
#include <iostream>
#include <fstream>
#define MOD 9999991
using namespace std;
ifstream fin("dirichlet.in");
ofstream fout("dirichlet.out");
int n;
int putere(long long x,long long n)
{
    if (n==0) return 1;
    if (n==1) return x%MOD;
    long long a=putere(x,n/2);
    a=a*a%MOD;
    if (n%2==1) a=a*x%MOD;
    return a;
}
int comb(long long n,long long k)
{
    long long t=1,s=1;
    for (int i=1;i<=n;i++)
    {
        s=s*i%MOD;
        if (i<=k) t=t*i%MOD;
        if (i<=n-k) t=t*i%MOD;
    }
    t=putere(t,MOD-2);
    return (s*t)%MOD;
}
int main()
{
    fin>>n;
    fout<<comb(2*n,n)/(n+1)%MOD;
    return 0;
}