Cod sursa(job #2809653)

Utilizator DesertChuStefan Andrei DesertChu Data 27 noiembrie 2021 12:30:33
Problema Dirichlet Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.56 kb
#include <bits/stdc++.h>
#define M 9999991
using namespace std;
ifstream f("dirichlet.in");
ofstream g("dirichlet.out");
int x;
long long p(int vl, int n)
{
    if (n==0) return 1;
    if (n==1) return vl%M;
    long long y=p(vl,n/2);
    y=(y*y)%M;
    if (n%2==1) y=y*vl%M;
    return y;
}
long long catalan(long long n)
{
    long long i,s=1,t=1;
    for(i=1;i<=2*n;i++)
    {
        if(i>=n+2) s=(s*i)%M;
        if(i<=n) t=(t*i)%M;
    }
    t=p(t,M-2);
    return (s*t)%M;
}
int main()
{
    f>>x;
    g<<catalan(x);
    return 0;
}