uva 839 Not so Mobile

题目：Not so Mobile

题意：有一串吊在一起的杠杆，问是否能平衡。按dfs序输入杠杆。

思路：dfs。

代码：

#include<cstdio>#include<iostream>#include<string>#include<cstring>#include<vector>#include<set>#include<map>#include<algorithm>#include<cmath>#include<queue>#include<stack>#include<deque>using namespace std;int dfs(){int w1,d1,w2,d2;scanf("%d%d%d%d",&w1,&d1,&w2,&d2);int l=w1,r=w2;if(w1==0) l=dfs();if(w2==0) r=dfs();if(l*d1==r*d2&&r!=-1&&l!=-1) return l+r;return -1;}int main() {int T;scanf("%d",&T);while(T--){if(dfs()==-1) printf("NO\n");else printf("YES\n");if(T) printf("\n");}return 0;}