数论——扩展的欧几里德算法 - HDU2669

#include <iostream>
using namespace std;

int gcd(int a, int b, int &x, int &y) {
    if (b == 0) {
        x = 1, y = 0;
        return a;
    }
    int q = gcd(b, a%b, y, x);
    y -= a / b * x;
    return q;
}

int main() {
    int a, b;
    while (scanf("%d%d", &a, &b) != EOF) {
        int x, y;
        if (gcd(a, b, x, y) != 1)
            cout << "sorry" << endl;
        else {
            if (x < 0) {
                x += b; y -= a;
            }
            cout << x << " " << y << endl;
        }
    }
    return 0;
}