here we go bitch!

#include <stdio.h>
#include <gmp.h>

typedef mpz_t ll;

void extended_euclidian(ll a, ll b, ll* d, ll* x, ll* y){
    if(mpz_cmp_ui(b, 0) == 0) {
        mpz_set(*d, a);
        mpz_set_ui(*x, 1);
        mpz_set_ui(*y, 0);
    } else {
        ll r;
        mpz_init(r);
        mpz_tdiv_r(r, a, b);
        extended_euclidian(b, r, d, x, y);

        ll xp, tmp, tmp2;
        mpz_init(tmp);
        mpz_init(tmp2);
        mpz_init_set(xp, *y);
        mpz_tdiv_q(tmp, a, b);
        mpz_mul(tmp2, tmp, *y);
        mpz_sub(tmp, *x, tmp2);
        mpz_set(*y, tmp);
        mpz_set(*x, xp);
    }
}

int main(int argc, char *argv[]) {
    if (argc < 3) {
        printf("Usage: example number1 number2\n");
        return 1;
    }

    ll a, b, d, x, y;
    mpz_init(d);
    mpz_init(x);
    mpz_init(y);

    mpz_init_set_str(a, argv[1], 10);
    mpz_init_set_str(b, argv[2], 10);

    extended_euclidian(a, b, &d, &x, &y);

    char* str_a = mpz_get_str(NULL, 10, a);
    char* str_b = mpz_get_str(NULL, 10, b);
    char* str_d = mpz_get_str(NULL, 10, d);
    char* str_x = mpz_get_str(NULL, 10, x);
    char* str_y = mpz_get_str(NULL, 10, y);

    printf("a*x + b*y = mdc(a, b) tal que\na \t= \t%s\nb \t= \t%s\nmdc(a, b) = \t%s\nx \t= \t%s\ny \t= \t%s\n",
            str_a, str_b, str_d, str_x, str_y);

    return 0;
}