README.md

371. Sum of Two Integers

Calculate the sum of two integers a and b, but you are not allowed to use the operator + and -.

Example 1:

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

Example 2:

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

Solutions (Rust)

1. Bitwise Operator

impl Solution {
    pub fn get_sum(a: i32, b: i32) -> i32 {
        let mut ans = 0;
        let mut mask = 1;
        let mut c = false;
        for _ in 0..32 {
            if (a & mask == b & mask && c) || (a & mask != b & mask && !c) {
                ans |= mask;
            }
            if a & mask != 0 && b & mask != 0 {
                c = true;
            }
            if a & mask == 0 && b & mask == 0 {
                c = false;
            }
            mask <<= 1;
        }
        ans
    }
}