Cod sursa(job #1649520)

Utilizator Matei_IgnutaMatei Ignuta Matei_Ignuta Data 11 martie 2016 13:58:36
Problema Invers modular Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.72 kb
#include <stdio.h>

using namespace std;

long long N, M;

long long phi(long long n){
    long long copy = n;
    for(long long i=2; i*i<=n; i++)
        if(n%i==0)
        {
            while(n%i==0) n=n/i;
            copy = (copy/i) * (i-1);
        }
    if(n!=1) copy = (copy/n)*(n-1);
    return copy;
    }
int main()
{
    freopen("inversmodular.in", "r", stdin);
    freopen("inversmodular.out", "w", stdout);
    scanf("%lld %lld", &N, &M);

    long long pow = phi(M) - 1;
    long long copy = N;
    long long crt = 1;
    for(long long p = 1;p <= pow;p <<= 1)
    {
        if (p & pow) crt = (crt * copy) % M;
        copy = (copy * copy) % M;
    }
    printf("%lld\n",crt);
    return 0;
}