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1963. Find XOR Sum of All Pairs Bitwise AND

My accepted Python solution to LeetCode problem 1963, Find XOR Sum of All Pairs Bitwise AND, running in 15ms.

  • Difficulty: Hard
  • Python
  • Runtime 15ms
  • Memory 31.2MB

Read the problem on LeetCode View on GitHub

The problem statement is LeetCode’s and stays on their site. What follows is my accepted solution.

Python

Accepted on LeetCode — runtime 15ms, memory 31.2MB, accepted 2026-01-02.

python
class Solution:
    def getXORSum(self, arr1: List[int], arr2: List[int]) -> int:
        # Key insight: XOR of (a AND b) for all pairs equals (XOR of arr1) AND (XOR of arr2)
        # This is because XOR distributes over AND in a specific way
        
        from functools import reduce
        from operator import xor
        
        xor1 = reduce(xor, arr1, 0)
        xor2 = reduce(xor, arr2, 0)
        
        return xor1 & xor2

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