Question

371. Sum of Two Integers

中文文档

Description

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

Solutions

Solution 1

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

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

class Solution {
public:
  int getSum(int a, int b) {
    while (b) {
      unsigned int carry = (unsigned int) (a & b) << 1;
      a = a ^ b;
      b = carry;
    }
    return a;
  }
};

func getSum(a int, b int) int {
  for b != 0 {
    s := a ^ b
    b = (a & b) << 1
    a = s
  }
  return a
}