Cod sursa(job #2341846)

Utilizator Cezar211Popoveniuc Cezar Cezar211 Data 12 februarie 2019 11:59:16
Problema Invers modular Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.8 kb
#include <bits/stdc++.h>
using namespace std;
ifstream fin ("inversmodular.in");
ofstream fout ("inversmodular.out");
int a, n, ind;
int putere(long long a, long long b)
{
    long long p = 1;
    while(b)
    {
        if(b%2==1)
            p=(p*a)%n;
        a=(a*a)%n;
        b/=2;
    }
    return p;
}
int indicator(int n)
{
    int f = 2, p, rez = 1;
    while(f*f<=n)
    {
        if(n%f == 0)
        {
             p = 0;
             while(n%f==0)
             {
                 p++;
                 n/=f;
             }
             rez*=putere(f, p-1)*(f-1);
        }
        f++;
    }
    if(n > 1)
        rez*=(n-1);
    return rez;
}
int main()
{
    fin >> a >> n;
    ind = indicator(n);
    a = putere(a, ind-1);
    fout << a;
    return 0;
}