Cod sursa(job #2175474)

Utilizator stelian2000Stelian Chichirim stelian2000 Data 16 martie 2018 17:23:18
Problema Invers modular Scor 60
Compilator cpp Status done
Runda Arhiva educationala Marime 0.59 kb
#include <cstdio>
#include <cmath>

using namespace std;

int n;

int rid_put(int a,int b)
{
    int sol=1;
    for(long long i=1;i<=b;i<<=1)
    {
        if(b&i) sol=(1LL*sol*a)%n;
        a=(1LL*a*a)%n;
    }
    return sol;
}

int main()
{
    freopen("inversmodular.in","r",stdin);
    freopen("inversmodular.out","w",stdout);
    int a;
    scanf("%d%d",&a,&n);
    int lim=sqrt(n);
    int fi=n-1;
    for(int i=2;i<=lim;i++)
        if(n%i==0)
        {
            fi--;
            if(n/i!=i) fi--;
        }
    printf("%d",rid_put(a,fi-1));
    return 0;
}