POJ 2362

#include <cstdio>
#include <algorithm>
using namespace std;
int a[100],big,sum,n,cas,v[100],flag;

int cmp(int a,int b){
return a>b;
}

int dfs(int k,int id,int res){
if(k==3)
return 1;
for(int i=id;i<=n;i++){
if(!v[i] && res>=a[i]){
v[i]=1;
if(res==a[i]){
if(dfs(k+1,1,sum/4))
return 1;
}else
if(dfs(k,i+1,res-a[i]))
return 1;
v[i]=0;
}
}
return 0;
}
int main() {
scanf("%d",&cas);
while(cas--){
big=0;
sum=0;
scanf("%d",&n);
for(int i=1;i<=n;i++){
scanf("%d",&a[i]);
if(a[i]>big)
big=a[i];
sum+=a[i];
}
flag=0;
if(sum%4!=0 || big>sum/4){
printf("no\n");
continue;
}
else{
sort(a+1,a+n+1,cmp);
for(int i=0;i<100;i++)
v[i]=0;
flag=dfs(0,1,sum/4);
}
if(flag!=0)
printf("yes\n");
else
printf("no\n");
}
return 0;
}