#include <stdio.h>

int main()

{

    int a = -;

    int b = -;

    a = a^b;

    b = a^b;

    a = a^b;

    /*或者简写为

     *

    a ^= b;

    b ^= a;

    a ^= b

    *

    **/

    printf("交换后a = %d,b = %d\n",a,b);

    return ;

}