[经验分享] "两数交换" 宏

#include <stdio.h>

 2#include <stdlib.h>

 3

 4#define SWAP0(a,b) \

 5            a= a^b,\

 6            b= a^b,\

 7            a= a^b

 8

 9#define SWAP2(a,b) \

10            { unsigned tempBuf[10];\

11              memcpy(tempBuf,&a,sizeof(a)); \

12              memcpy(&a,&b,sizeof(b)); \

13              memcpy(&b,tempBuf,sizeof(b));\

14             }

15

16#define SWAP3(a,b) \

17        { (sizeof(a) == sizeof(unsigned char)) ? SWAP0(*(unsigned char*)&a,*(unsigned char*)&b) :\

18          (sizeof(a) == sizeof(short)) ? SWAP0(*(short*)&a,*(short*)&b) :\

19          (sizeof(a) == sizeof(unsigned int)) ? SWAP0(*(unsigned int*)&a,*(unsigned int*)&b) :\

20          (sizeof(a) == sizeof(unsigned long long)) ? SWAP0(*(unsigned long long *)&a,*(unsigned long long *)&b):0;\

21         }  

22/***************************************

23  * Fuction:main

24 * Decri  :适应多种数据类型 

25 * Author :(欢迎关注公众号:最后一个bug) 

26***************************************/

27int main(int argc, char *argv[]) {

28

29    char ac  = 11;

30    char bc  = 88;

31

32    short a  = 11;

33    short b  = 88;

34

35    float af = 11;

36    float bf = 88;

37    printf("//***********SWAP2*********\n");

38    printf("ac = %d,bc = %d\n",ac,bc);

39    SWAP2(ac,bc);

40    printf("ac = %d,bc = %d\n",ac,bc);

41

42    printf("a = %d,b = %d\n",a,b);

43    SWAP2(a,b);

44    printf("a = %d,b = %d\n",a,b);

45

46    printf("af = %f,bf = %f\n",af,bf);

47    SWAP2(af,bf);

48    printf("af = %f,bf = %f\n",af,bf);

49

50    printf("//**********SWAP3************\n");

51    printf("ac = %d,bc = %d\n",ac,bc);

52    SWAP3(ac,bc);

53    printf("ac = %d,bc = %d\n",ac,bc);

54

55    printf("a = %d,b = %d\n",a,b);

56    SWAP3(a,b);

57    printf("a = %d,b = %d\n",a,b);

58

59    printf("af = %f,bf = %f\n",af,bf);

60    SWAP3(af,bf);

61    printf("af = %f,bf = %f\n",af,bf);

62

63   return 0;

64}