Cod sursa(job #2695150)

Utilizator razviOKPopan Razvan Calin razviOK Data 11 ianuarie 2021 22:32:26
Problema Invers modular Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.79 kb
#include <iostream>
#include <fstream>
using namespace std;
ifstream f("inversmodular.in");
ofstream g("inversmodular.out");
long long A,N,EulerTotient;
long long Phi(long long L)
{
    long long Prod=1;
    for(int i=2; i*i<=L; i++)
        if(L%i==0)
        {
            Prod=Prod*(i-1);
            L/=i;
            while(L%i==0)
            {
                Prod*=i;
                L/=i;
            }
        }

    if(L!=1)
        Prod*=(L-1);

    return Prod;
}
long long logPow()
{
    long long rez=1;
    while(EulerTotient)
    {
        if(EulerTotient%2)
            rez=(rez*A)%N;
        A=(A*A)%N;
        EulerTotient/=2;
    }
    return rez%N;
}
int main()
{
    f>>A>>N;
    EulerTotient=Phi(N)-1;
    g<<logPow();

    return 0;
}