#include<bits/stdc++.h> using namespace std; const int Max=20; int stick[Max]; bool visit[Max]; int m; int side; bool DFS(int sum,int number){ if(number==4){ cout<<"yes"<<endl; return true; } for(int i=0;i<m;i++){ if(visit[i]||sum+stick[i]>side){ continue; } visit[i]=1; if(sum+stick[i]==side){ if(DFS(0,number+1)){ return 1; } } else{ if(DFS(stick[i]+sum,number)){ return 1; } } visit[i]=0; } return 0; } bool Com(int x,int y){ return x>y; } int main() { int caseN; cin>>caseN; while(caseN--) { memset(visit,0,sizeof(visit)); int sum=0; cin>>m; for(int i=0; i<m; i++) { cin>>stick[i]; sum+=stick[i]; } side=sum/4; if(!DFS(0,0)){ cout<<"no"<<endl; } } return 0; } 不剪枝