剑指Offer47 不用加减乘除做加法

 1 /*************************************************************************
 2     > File Name: 47_AddTwoNumbers.c
 3     > Author: Juntaran
 4     > Mail: JuntaranMail@gmail.com
 5     > Created Time: 2016年09月04日 星期日 21时33分07秒
 6  ************************************************************************/
 7  
 8 #include <stdio.h>
 9 
10 // 移位求两数相加
11 int ADD(int num1, int num2)
12 {
13     int sum, carry;
14     if (num1 == 0)
15         return num2;
16     if (num2 == 0)
17         return num1;
18     
19     while (num2 != 0)
20     {
21         sum = num1 ^ num2;
22         carry = (num1 & num2) << 1;
23         
24         num1 = sum;
25         num2 = carry;
26     }
27     return sum;
28 }
29 
30 int main()
31 {
32     int num1 = 5;
33     int num2 = 37;
34     
35     int sum = ADD(num1, num2);
36     printf("sum is %d\n", sum);
37     return 0;
38 }