Cod sursa(job #1902596)

Utilizator feli2felicia iuga feli2 Data 4 martie 2017 18:02:48
Problema Invers modular Scor 40
Compilator cpp Status done
Runda Arhiva educationala Marime 0.42 kb
#include <iostream>
#include <fstream>

using namespace std;

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

int a, n;

int lgpow(int x, int p)
{
    int r=1;
    for(int i=0;(1<<i)<=p;i++)
    {
        if((1<<i)&p)
        {
            r=(1ll*x*r)%n;
        }
        x=(1ll*x*x)%n;
    }
    return r;
}

int main()
{
    fin>>a>>n;
    fout<<lgpow(a,n-2);
    return 0;
}