Cod sursa(job #1974527)

Utilizator usureluflorianUsurelu Florian-Robert usureluflorian Data 27 aprilie 2017 22:22:19
Problema Dirichlet Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.5 kb
#include <fstream>
#define MOD 9999991
using namespace std;
ifstream f ("dirichlet.in");
ofstream g ("dirichlet.out");
long long n;
long long invers(long long a,long long b)
{
    long long p=1;
    while(b)
    {
        if(b&1) p=p*a%MOD;
        a=a*a%MOD;
        b>>=1;
    }
    return p%MOD;
}
int main()
{
    f>>n;
    long long n2=2*n,a=1,b=1;
    for(int i=n2;i>n+1;--i) a=a*i%MOD;
    for(int i=1;i<=n;++i) b=b*i%MOD;
    g<<a*invers(b,MOD-2)%MOD<<'\n';
    return 0;
}