XOR.cpp

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

int findSubarrCnt(int arr[], int n)
{
    int ans = 0, XOR = 0;

    // Array to store prefix XOR's
    int prefix[n];

    for (int i = 0; i < n; ++i) {

        // Calculate XOR until this index
        XOR = XOR ^ arr[i];

        // Store the XOR in prefix array
        prefix[i] = XOR;
        // cout<<"Prefix at "<<i<<" ="<<XOR<<endl;
    }

    unordered_map<int, vector<int>> group;

    

    for (int i = 0; i < n; ++i) {
            group[prefix[i]].push_back(i);
        }

    for(auto x: group){
        // cout<<endl<<"Prefix = "<<x.first<<endl;

        vector<int> temp = x.second;
        if(x.first==0)
            ans+=temp[0];
        for(int i=0;i<temp.size()-1;i++){
            // cout<<temp[i]<<" "<<temp[i+1]<<endl;
            ans+=temp[i+1]-temp[i]-1;
        }

    }

    return ans;
}

// Driver Code
int main()
{
   int T;
	int N;
	cin>>T;
	while(T--){
	    cin>>N;
	    int a[N];
	    for(int i=0;i<N;i++)
	        cin>>a[i];
	        
         cout <<findSubarrCnt(a, N)<<endl;
	}
    return 0;
}