Cod sursa(job #2631136)

Utilizator PetyAlexandru Peticaru Pety Data 29 iunie 2020 09:56:30
Problema Dirichlet Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.65 kb
#include <bits/stdc++.h>

using namespace std;

ifstream fin ("dirichlet.in");
ofstream fout ("dirichlet.out");

int n;
const int mod = 9999991;

int logpow (int a, int b) {
  int p = 1;
  while (b) {
    if (b & 1)
      p = 1ll * p *  a% mod;
    a = 1ll * a * a % mod;
    (b >>= 1);
  }
  return p;
}

int main()
{
  ios_base::sync_with_stdio(false);
  cin.tie(0); cout.tie(0);
  fin >> n;
  long long f1, f2;
  f1 = f2 = 1;
  for (int i = n + 2; i <= 2 * n; i++) {
    f1 *= i;
    f1 %= mod;
  }
  for (int i = 1; i <= n; i++) {
    f2 *= i;
    f2 %= mod;
  }
  fout << 1ll * f1 * logpow(f2, mod - 2) % mod;
  return 0;
}