扩展的欧几里得算法

#include<bits/stdc++.h>//ax+by=gcd(a,b) x=? y=?
using namespace std;
int extend_gcd(int a,int b,int &x,int &y){
    int ret,tmp;
    if(!b){
        x=1;
        y=0;
        return a;
    }
    ret=extend_gcd(b,a%b,x,y);
    tmp=x;
    x=y;
    y=tmp-a/b*y;
    return ret;
}
int main(){
    int a,b,x,y,z;
    cin>>a>>b;
    z=extend_gcd(a,b,x,y);
    cout<<x<<""<<y<<""<<z;
    return 0;
}