c
/*
* @Author: 无涯 (mxl233@qq.com)
* @Date: 2023-08-03 21:52:38
* @LastEditors: 开心好梦🥳
* @LastEditTime: 2023-08-07 21:50:59
* @FilePath: ex-14.c
*/
#include <stdio.h>
#define swap(t,x,y) t tmp = x; \
x = y; \
y = tmp;
#if SYSTEM == SYSV
#define HDR "stdio.h"
#elif SYSTEM == BSD
#define HDR "bsd.h"
#elif SYSTEM == MSDOS
#define HDR "msdos.h"
#else
#define HDR "default.h"
#endif
#include HDR
int main(){
int x , y;
x = 2;
y = 3;
swap(int, x, y);
printf("x = %d, y = %d \n", x, y);
return 0;
}