#include <bits/stdc++.h>
using namespace std;
int main() {
  long long t, n, i, j, c, d;
  cin >> t;
  while (t--) {
    c = 0;
    d = 0;
    cin >> n;
    long long a[n];
    long long b[n - 1];
    for (i = 0; i < n; i++) {
      cin >> a[i];
    }
    if (n == 1)
      cout << "YES" << endl;
    else {
      sort(a, a + n);
      for (i = 0, j = 0; i < n - 1, j < n - 1; i++, j++) {
        b[j] = a[i + 1] - a[i];
      }
      for (j = 0; j < n - 1; j++) {
        if (abs(b[j]) > 1) c += 1;
      }
      if (c)
        cout << "NO" << endl;
      else
        cout << "YES" << endl;
    }
  }
  return 0;
}
