1442. Count Triplets That Can Form Two Arrays of Equal XOR.cpp

class Solution {
public:
    int countTriplets(vector<int>& arr) {
        vector<int> prefixXor(begin(arr), end(arr));

        prefixXor.insert(prefixXor.begin(), 0);
        int n = prefixXor.size();

        for(int i = 1; i < n; i++) {
            prefixXor[i] ^= prefixXor[i-1];
        }

        int triplets = 0;

        for(int i = 0; i < n; i++) {
            for(int k = i+1; k < n; k++) {

                if(prefixXor[k] == prefixXor[i]) {
                    triplets += k-i-1;
                }

            }
        }

        return triplets;
    }
};