B - 可能的路径（gcd变形）

https://vjudge.net/contest/218366#problem/B

要不是在数学题专题里，我估计就盲目搜索了。10^18范围1s应该过不去。

再细看能感觉到是gcd的变形，但是具体结论说不上来。

推导参考：https://blog.csdn.net/LuRiCheng/article/details/54729531

 #include<iostream>
 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 #include<cstdlib>
 #include<cmath>
 #include<vector>
 #include<stack>
 #include<queue>
 #define lson l, m, rt<<1
 #define rson m+1, r, rt<<1|1
 #define IO ios::sync_with_stdio(false);cin.tie(0);
 #define INF 0x3f3f3f3f
 #define MAXN 100010
 const int MOD=1e9+;
 typedef long long ll;
 using namespace std;
 ll n, a, b, x, y;
 ll gcd(ll a, ll b)
 {
     if(a%b == )
         return b;
     return gcd(b, a%b);
 }
 int main()
 {
     IO;
     cin >> n;
     while(n--){
         cin >> a >> b >> x >> y;
         if(gcd(a, b) == gcd(x, y))
             cout << "Yes" << endl;
         else
             cout << "No" << endl;
     }
     return ;
 }