Cod sursa(job #1944803)

Utilizator tudortarniceruTudor Tarniceru tudortarniceru Data 29 martie 2017 11:32:41
Problema Invers modular Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.51 kb
#include <fstream>
#include <cstring>
#include <algorithm>
using namespace std;

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

int a, n;

int exp(int x, int y) {

    int r = 1;
    for (int i = 0; (1 << i) <= y; ++i) {
        if ((1 << i) & y) {
            r *= x;
            r %= n;
        }
        x = x * x;
        x = x % n;
    }

    return r;
}

int main() {

    fin >> a >> n;
    fout << exp(a, n - 2) % n;

    fout.close();
    return 0;
}