LeetCode 371 Sum of Two Integers - Implementation

The approach

Simulate addition with XOR and AND.

def getSum(a, b): mask = 0xFFFFFFFF while b & mask: carry = (a & b) << 1 a = a ^ b b = carry return a if b == 0 else ~(a ^ mask)

O(1)O(1) time, O(1)O(1) space.