#include <bits/stdc++.h>   using namespace std;   int main() {     int t, g = 0;     cin >> t;     for (int i = 0; i < t; i++) {       vector<int> p;       int n, x;       g = 0;       cin >> n;       if (n == 1) {         cin >> x;         cout <<  YES  << endl;         continue;       }       for (int l = 0; l < n; l++) {         int k;         cin >> k;         p.push_back(k);       }       sort(p.begin(), p.end());       for (int j = 0; j < p.size() - 1; j++) {         if (abs(p[j] - p[j + 1]) > 1) {           cout <<  NO  << endl;           g = 1;           break;         }       }       if (g == 0) cout <<  YES  << endl;     }     return 0;   }   