Help me in solving XSQR problem

help
,
1

My issue

I am submitting this solution in O(n2) time but my solution is not being accepted.

My code

#include <bits/stdc++.h>
using namespace std;

int main() {
	// your code goes here
    int t;
    
    cin>>t;
    while(t--){
        unordered_map<int,int> mp;
        int n;
        cin>>n;
        int arr[n];
        
        long long ans =0;
        for(int i=0;i<n;i++){
            cin>>arr[i];
            for(int j=i-1;j>=0;j--){
                mp[arr[i]^arr[j]]++;
                ans+=mp[arr[i]^arr[j]]-1;
            }
        }

        cout<<ans*8<<endl;
    }
}

Problem Link: Xometry (Easy Version) Practice Coding Problem