擴展歐幾里得

#include <iostream>
#include <algorithm>
#include <cstring>
#include <functional>
#include <cstdio>
#include <vector>
#include <queue>
#include <limits>
using namespace std;

typedef long long ll;
const int MAXN = 100005;

int extgcd(int a, int b, int &x, int &y)
{
    if (b == 0)
    {
        x = 1;
        y = 0;
        return a;
    }
    int xx, yy;
    int ret = extgcd(b, a % b, xx, yy);
    x = yy;
    y = xx - (a / b) * yy;
    return ret;
}

int main()
{
    freopen("in.txt", "r", stdin);
    freopen("out.txt", "w", stdout);
    ios::sync_with_stdio(false);
    cin.tie(0);
    int x, y;
    extgcd(4, 11, x, y);
    cout << x << " " << y;

    return 0;
}