Can anyone explain the last part of the following code to check for overflow? The code is the solution for LeetCode question 137. Single Number II. I know it might be overflowing due to the MSB is set. Base on the problem statement, the number must be in - 2^31 ~ 2^31-1. We can use deduction to correct the overflow. But can we use mask i.e. 0x7FFF FFFF FFFF FFFF to solve that? I think it is No. Since the precision is infinite in Python, the mask method would not work. Is that correct? class Solution: def singleNumber(self, nums: List[int]) -> int: # Loner. loner = 0 # Iterate over all bits for shift in range(32): bit_sum = 0 # For this bit, iterate over all integers for num in nums: # Compute the bit of num, and add it to bit_sum bit_sum += (num >> shift) & 1 # Compute the bit of loner and place it loner_bit = bit_sum % 3 loner = loner | (loner_bit << shift) # Do not mistaken sign bit for MSB. if loner >= (1 << 31): loner = loner - (1 << 32) return loner Continue reading...
