Cod sursa(job #2506944)

Utilizator davidcotigacotiga david davidcotiga Data 9 decembrie 2019 08:49:28
Problema Dirichlet Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.56 kb
#include <fstream>

using namespace std;

ifstream cin("dirichlet.in");
ofstream cout("dirichlet.out");

const int MOD = 9999991;

long long power(long long a, int b){
    long long p = 1;
    while (b){
        if (b & 1){
            p = p * a % MOD;
        }
        a = a * a % MOD;
        b >>= 1;
    }
    return p;
}


int main()
{
    long long a = 1, b = 1, n, i;
    cin >> n;
    for(i = 2; i <= n; i++){
        a = a * (n + i) % MOD;
        b = b * i % MOD;
        }
    cout << a * power(b, MOD - 2) % MOD;
    return 0;
}