371. Sum of Two Integers

Given two integers a and b, return the sum of the two integers without using the operators + and -.

Example 1:

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

Example 2:

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

Constraints:

• -1000 <= a, b <= 1000

Solution:

class Solution {
    public int getSum(int a, int b) {
        while (b != 0) {
            int carry = (a & b) << 1; // 1    <-  10
            a = a ^ b;
            b = carry;
        }

        return a;
    }
}

// TC: O(n)
// SC: O(1)