Cod sursa(job #3147928)

Utilizator proflaurianPanaete Adrian proflaurian Data 28 august 2023 10:29:12
Problema Invers modular Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.69 kb
#include <bits/stdc++.h>
using namespace std;
ifstream f("inversmodular.in");
ofstream g("inversmodular.out");
int64_t a,n,e;
int64_t produs(int64_t x,int64_t y)
{
    x=1LL*x*y%n;
    return x;
}
int64_t phi(int64_t n)
{
    int64_t e=n;
    for(int64_t d=2;d*d<=n;d++)
        if(n%d==0)
        {
            e=e/d*(d-1);
            while(n%d==0)
                n/=d;
        }
    if(n>1)
        e=e/n*(n-1);
    return e;
}
int64_t putere(int64_t b,int64_t e)
{
    if(e==0)
        return 1;
    int64_t r=putere(b,e/2);
    r=produs(r,r);
    if(e%2==1)r=produs(r,b);
    return r;
}
int main()
{
    f>>a>>n;
    g<<putere(a,phi(n)-1);
    return 0;
}