面试题 65. 不用加减乘除做加法

输入: a = 1, b = 1
输出: 2

class Solution:
    def add(self, a: int, b: int) -> int:
        a, b = a & 0xffffffff, b & 0xffffffff
        s = carry = 0
        while b:
            s = a ^ b
            carry = ((a & b) << 1) & 0xffffffff
            a, b = s, carry
        return a if a < 0x80000000 else ~(a ^ 0xffffffff)

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

class Solution {
    public int add(int a, int b) {
        if (b == 0) return a;
        return add(a ^ b, (a & b) << 1);
    }
}

/**
 * @param {number} a
 * @param {number} b
 * @return {number}
 */
var add = function (a, b) {
  if (b == 0) return a;
  return add(a ^ b, (a & b) << 1);
};

func add(a int, b int) int {
    if b == 0 {
        return a
    }
    return add(a ^ b, (a & b) << 1)
}