Practice/Meta/Leetcode 371. Sum of Two Integers

Leetcode 371. Sum of Two Integers

CodingMust

Problem

Implement a function that calculates the sum of two integers without using the addition (+) or subtraction (-) operators. You must rely solely on bitwise operations to perform the calculation.

The challenge requires understanding how binary addition works at the bit level: computing the sum bits and the carry bits separately, then combining them iteratively until no carry remains.

Requirements

1. Calculate the sum of two integers using only bitwise operators
2. Do not use the + or - operators anywhere in your solution
3. Handle both positive and negative integers correctly
4. Your solution should work with two's complement representation of negative numbers

Constraints

• -1000 ≤ a, b ≤ 1000
• The result will fit within a 32-bit signed integer
• Time complexity should be O(1) - bounded by the fixed bit width
• Space complexity should be O(1)

Examples

Example 1:

Input: a = 3, b = 2 Output: 5 Explanation: Binary addition without arithmetic operators: 011 + 010 = 101

Example 2:

Input: a = -2, b = 3 Output: 1 Explanation: Two's complement handles negative numbers correctly

Example 3:

Input: a = 0, b = 0 Output: 0 Explanation: Sum of zeros is zero