CF 7C. Line(扩展欧几里德)

题目链接

AC了。经典问题，a*x+b*y+c = 0整数点，有些忘记了扩展欧几里德，复习一下。

#include <cstdio>
#include <iostream>
#include <cmath>
using namespace std ;
#define LL __int64
LL x,y;
LL ext_eulid(LL a,LL b)
{
    LL t,d;
    if(b == 0)
    {
        x = 1;
        y = 0;
        return a;
    }
    d = ext_eulid(b,a%b);
    t = x;
    x = y;
    y = t - (a/b)*y;
    return d;
}
int main()
{
    LL A,B,C,d;
    cin>>A>>B>>C;
    d = ext_eulid(A,B);
    if((-C)%d != 0)
    {
        printf("-1
");
    }
    else
    {
        x = x*((-C)/d);
        y = y*((-C)/d);
        cout<<x<<" "<<y<<endl;
    }
    return 0;
}