Codeforces Beta Round #7 C. Line (扩展欧几里德)

题目链接：http://codeforces.com/problemset/problem/7/C

给你一个直线方程，有整数解输出答案，否则输出-1。

扩欧模版题。这里有讲解：http://www.cnblogs.com/Recoder/p/5459812.html

(很久没写exgcd，都不会写了)

 #include <bits/stdc++.h>
 using namespace std;
 typedef long long LL;

 LL exgcd(LL a , LL b , LL &x , LL &y) {
     LL res = a;
     if(!b) {
         x =  , y = ;
     }
     else {
         res = exgcd(b , a % b , x , y);
         LL temp = x;
         x = y;
         y = temp - a / b * y;
     }
     return res;
 }

 int main()
 {
     LL a , b , c , gcd , x , y;
     cin >> a >> b >> c;
     gcd = exgcd(a , b , x , y);
     if(c % gcd == ) {
         LL temp = -c / gcd;
         cout << x * temp << " " << y * temp << endl;
     }
     else {
         cout << - << endl;
     }
 }