#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

bool solve(){

    int n;cin>>n;

    int a[n];for(int &i:a) cin>>i;

    ll sum=0;

    for(int i=0;i<n;i++){

        sum+=a[i];

        if(sum<=0) return 0;

    }

    sum=0;

    for(int i=n-1;i>=0;i--){

        sum+=a[i];

        if(sum<=0) return 0;

    }

    return 1;

}    

int main(){

    int t;cin>>t;

    while(t--)

        cout<<(solve()?"YES":"NO")<<"\n";

    return 0;

}