Subarray with given XOR

Problem

Given an array of integers A and an integer B.

Find the total number of subarrays having bitwise XOR of all elements equals to B.

Solution Approach

Expected Time complexity: $O(n)$

Click - to see solution code

C++

int Solution::solve(vector<int> &A, int B) {
    int n = A.size();
    int xorr = 0;
    unordered_map<int, int> mp;
    mp[0] = 1;
    int ans = 0;
    for (int i = 0; i < n; i++) {
        xorr ^= A[i];
        if (mp.find(xorr ^ B) != mp.end()) {
            ans += mp[xorr ^ B];
        }
        mp[xorr]++;
        ;
    }
    return ans;
}