[模板] Exgcd

求解一组ax+bc=gcd(a,b)

#include<iostream>
#include<cstdio>

using namespace std;

int exgcd(int A,int B,int &x,int &y){
  if(B==0){
    x=1;y=0;return A;
  }
  int ret=exgcd(B,A%B,x,y);
  int t=x;x=y;y=t-A/B*y;
  return ret;
}

int main(){
  int a,b,x,y;
  while(cin>>a>>b){
    int g=exgcd(a,b,x,y);
    cout<<a<<"*"<<x<<"+"<<b<<"*"<<y<<"="<<g<<endl;
  }
}