用位运算实现加减法

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 using namespace std;
 5 
 6 int get(int a, int b) {
 7     int c = a ^ b;
 8     int d = ( a & b ) << 1;
 9     if(c == 0 || d == 0) {
10         return c ^ d;
11     }
12     return get(c, d);
13 }
14 
15 int main() {
16     int a, b;
17     while(EOF != scanf("%d %d",&a, &b) ) {
18         printf("%d\n", get(a, b) );
19     }
20     return 0;
21 }