Cod sursa(job #590995)

Utilizator bixcabc abc bixc Data 21 mai 2011 15:52:18
Problema Invers modular Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.53 kb
#include <stdio.h>

#define ll long long

int A, N;

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

int main()
{
    ll inv = 0, ins;

    freopen("inversmodular.in", "r", stdin);
    freopen("inversmodular.out", "w", stdout);

    scanf("%d %d", &A, &N);
    gcd(inv, ins, A, N);

    if (inv < 0)
       //inv = N + inv % N;
       inv+= N;

    printf("%lld\n", inv);

    return 0;
}