#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n;
    cin >> n;
    int a[n];
    for (int i = 0; i < n; i++) cin >> a[i];
    sort(a, a + n);
    int pre[n - 1];
    bool flag = 1;
    for (int i = 0; i < n - 1; i++) {
      pre[i] = a[i + 1] - a[i];
      if (abs(pre[i]) > 1) {
        flag = 0;
        cout << "NO"
             << "\n";
        break;
      }
    }
    if (flag == 1)
      cout << "YES"
           << "\n";
  }
  return 0;
}
