交换两个变量（不创建临时变量）

#include <stdio.h>
int main()
{
    
    
 int a = 13;
 int b = 77;
 a = a^b;
 b = a^b;
 a = a^b;
 printf("a = %d\nb = %d\n", a, b);
 return 0;
}