P1292 倒酒

传送门

数学题

扩展gcd

#include<bits/stdc++.h>
using namespace std;
int exgcd(int a,int b,int &x,int &y){
    if(!b){
        x=1;
        y=0;
        return a;
    }
    int r=exgcd(b,a%b,x,y);
    int t=x;
    x=y;
    y=t-a/b*y;
    return r;
}
int main(){
    int x,y,a,b;
    cin>>a>>b;
    int gcd=exgcd(a,b,x,y);
    cout<<gcd<<endl;
    x*=-1;
    a*=-1;
    while(x<0||y<0){
        x+=b/gcd*(x<0);
        y-=a/gcd*(x>=0);
    }
    cout<<x<<" "<<y;
    return 0;
}