Cod sursa(job #2456315)

Utilizator FastmateiMatei Mocanu Fastmatei Data 14 septembrie 2019 10:29:07
Problema Invers modular Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.66 kb
#include <bits/stdc++.h>

using namespace std;

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

int Phi(int n)
{
    int sol,p;
    sol=n;
    for(p=2;n>1 && p*p<=n;p++)
        if(n%p==0)
        {
            sol=sol/p*(p-1);
            while(n%p==0)
                n/=p;
        }
    if(n>1) sol=sol/n*(n-1);
    return sol;
}

int PLog(int a,int n,int MOD)
{
    int sol=1;
    while(n>0)
    {
        if(n%2==1)
            sol=1LL*sol*a%MOD;
        n/=2;
        a=1LL*a*a%MOD;
    }
    return sol;
}

int main()
{
    int b,n,a;
    fin>>a>>n;
    b=PLog(a,Phi(n)-1,n);
    fout<<b;
    return 0;
}