位运算：不用加减乘除做加法

Posted 2020-11-24 icehole

 1 /* 异或运算代表不进位的加法
 2     与右移代表进位
 3     一直相加直到进位为0为止
 4   */
 5 class Solution {
 6 public:
 7     int Add(int num1, int num2)
 8     {
 9         while(num2 != 0){
10             int sum = num1 ^ num2;
11             int carry = (num1 & num2) << 1;
12             num1 = sum;
13             num2 = carry;
14         }
15         return num1;
16     }
17 };