#include <bits/stdc++.h>
using namespace std;
void input(long long ara[], long long n) {
  for (long long i = 0; i < n; i++) cin >> ara[i];
}
void output(long long ara[], long long n) {
  for (long long i = 0; i < n; i++) cout << ara[i] << " ";
}
long long mx1(long long ara[], long long n) {
  long long mx = -1;
  for (long long i = 0; i < n; i++)
    if (ara[i] > mx) mx = ara[i];
  return mx;
}
long long mn1(long long ara[], long long n) {
  long long mn = 1e18;
  for (long long i = 1; i <= n; i++)
    if (ara[i] < mn) mn = ara[i];
  return mn;
}
int maxSubArraySum(long long a[], long long size) {
  long long max_so_far = INT_MIN, max_ending_here = 0;
  for (long long i = 0; i < size; i++) {
    max_ending_here = max_ending_here + a[i];
    if (max_so_far < max_ending_here) max_so_far = max_ending_here;
    if (max_ending_here < 0) max_ending_here = 0;
  }
  return max_so_far;
}
int main() {
  (ios_base::sync_with_stdio(false), cin.tie(NULL));
  long long t;
  cin >> t;
  while (t--) {
    long long n;
    cin >> n;
    long long ara[n + 1];
    input(ara, n);
    long long k = 0, sum = 0;
    for (long long i = 0; i < n; i++) {
      sum += ara[i];
      if (sum <= 0) {
        k = 1;
      }
    }
    sum = 0;
    for (long long i = n - 1; i >= 0; i--) {
      sum += ara[i];
      if (sum <= 0) {
        k = 1;
        break;
      }
    }
    if (k == 1)
      cout << "NO" << endl;
    else
      cout << "YES" << endl;
  }
}
