Cod sursa(job #2170886)

Utilizator TudorFinaruTudor Cristian Finaru TudorFinaru Data 15 martie 2018 10:13:01
Problema Invers modular Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.58 kb
#include <fstream>
using namespace std;
ifstream f("inversmodular.in");
ofstream g("inversmodular.out");
int a,n;

void euclid_e(long long &x, long long &y, int a, int b)
{
    if(!b) x=1,y=0;
    else{
        euclid_e(x,y,b,a%b);
        long long aux=x;
        x=y;
        y=aux-y*(a/b);
    }
}

long long inversmodular(int a, int MOD)
{
    long long inv=0, ins;
    euclid_e(inv, ins, a, MOD);
    if(inv<=0) inv=n+inv%MOD;
    return inv;
}

int main()
{
    f>>a>>n;
    g<<inversmodular(a,n)<<'\n';
    f.close();
    g.close();
    return 0;
}