#include <bits/stdc++.h>   using namespace std;   int main() {     int t;     cin >> t;     while (t--) {       int n;       cin >> n;       long long int a[n];       unordered_map<long long int, long long int> mp;       for (int i = 0; i < n; i++) {         cin >> a[i];         mp[a[i]]++;       }       if (mp.size() == 1)         cout <<  NO  << endl;       else {         cout <<  YES  << endl;         int f = -1, s = -1;         for (int i = 1; i < n; i++) {           if (a[i] != a[0]) {             f = i;             break;           }         }         for (int i = 1; i < n; i++) {           if (a[i] != a[f])             cout << i + 1 <<     << f + 1 << endl;           else             cout << 1 <<     << i + 1 << endl;         }       }     }   }   