UVa839

这个引用好精髓。

 #include <iostream>
 #include <cstring>
 #include <string>
 #include <map>
 #include <set>
 #include <algorithm>
 #include <fstream>
 #include <cstdio>
 #include <cmath>
 #include <stack>
 #include <queue>
 using namespace std;
 const double Pi=3.14159265358979323846;
 typedef long long ll;
 const int MAXN=+;
 const int dx[]={,,,,-};
 const int dy[]={,-,,,};
 const int INF = 0x3f3f3f3f;
 const int NINF = 0xc0c0c0c0;
 const ll mod=1e9+;

 bool solve(int &w)
 {
     int w1,w2,d1,d2;
     cin>>w1>>d1>>w2>>d2;
     bool b1=true,b2=true;
     if(!w1) b1=solve(w1);
     if(!w2) b2=solve(w2);
     w=w1+w2;
     return (b1&&b2&&(d1*w1==d2*w2));
 }

 int main()
 {
     int t;cin>>t;
     while(t--)
     {
         int w;
         if(solve(w)) cout <<"YES\n";
             else cout <<"NO\n";
         if(t) cout<<"\n";
     }
     return ;
  }