HackerEarth Minimum AND xor OR problem solution

In this HackerEarth Minimum AND xor OR problem solution, You are given an array A of N integers. Determine the minimum value of the following expression for all valid i,j:

(Ai and Aj) xor (Ai or Aj), where i != j.

#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;

int main()
{
    ll t;
    cin>>t;
    while(t--)
    {
        ll n;
        cin>>n;
        ll a[n];
        for(ll i=0;i<n;i++)
            cin>>a[i];
        sort(a,a+n);
        ll ans = INT_MAX;
        for(ll i=0;i<n-1;i++)
        {
            ans = min(ans, a[i]^a[i+1]);
        }
        cout<<ans<<"n";
    }
    return 0;
}