1835. Find XOR Sum of All Pairs Bitwise AND

Problem

The XOR sum of a list is the bitwise XOR of all its elements. If the list only contains one element, then its XOR sum will be equal to this element.

• For example, the XOR sum of [1,2,3,4] is equal to 1 XOR 2 XOR 3 XOR 4 = 4, and the XOR sum of [3] is equal to 3.

You are given two 0-indexed arrays arr1 and arr2 that consist only of non-negative integers.

Consider the list containing the result of arr1[i] AND arr2[j] (bitwise AND) for every (i, j) pair where 0 <= i < arr1.length and 0 <= j < arr2.length.

Return **the *XOR sum* of the aforementioned list**.

  Example 1:

Input: arr1 = [1,2,3], arr2 = [6,5]
Output: 0
Explanation: The list = [1 AND 6, 1 AND 5, 2 AND 6, 2 AND 5, 3 AND 6, 3 AND 5] = [0,1,2,0,2,1].
The XOR sum = 0 XOR 1 XOR 2 XOR 0 XOR 2 XOR 1 = 0.

Example 2:

Input: arr1 = [12], arr2 = [4]
Output: 4
Explanation: The list = [12 AND 4] = [4]. The XOR sum = 4.

  Constraints:

• 1 <= arr1.length, arr2.length <= 10^5

• 0 <= arr1[i], arr2[j] <= 10^9

Solution

class Solution {
    public int getXORSum(int[] arr1, int[] arr2) {
        int xor1 = 0;
        int xor2 = 0;
        for (int i : arr1) {
            xor1 ^= i;
        }
        for (int j : arr2) {
            xor2 ^= j;
        }
        return xor1 & xor2;
    }
}

Explain:

nope.

Complexity:

• Time complexity : O(n).
• Space complexity : O(n).