Sum of Two Integers Without Using + or - Operators

Given two integers a and b, compute their sum without using the + or - operators.

Example 1: Input: a = 1, b = 2 → Output: 3

Example 2: Input: a = 2, b = 3 → Output: 5

Solution Idea: Use bitwise operations. The XOR of a and b gives the sum without carry, while the AND (shifted left) gives the carry. Repeat until the carry becomes zero.

Java implementation:

class Solution {
    public int getSum(int a, int b) {
        while (b != 0) {
            int temp = a ^ b;
            b = (a & b) << 1;
            a = temp;
        }
        return a;
    }
}

Python implementation:

class Solution:
    def getSum(self, a: int, b: int) -> int:
        while b != 0:
            temp = a ^ b
            b = (a & b) << 1
            a = temp
        return a

Complexity Analysis: Time complexity O(1) (constant number of iterations for fixed‑size integers); space complexity O(1).