不允许创建临时变量，交换两个数的内容

思路1：加减

#include <stdio.h>
int main()
{
    int x=3;
    int y=2;
    x = x + y;
    y = x - y;
    x = x - y;
    printf("%d,%d\n", x, y);
    return 0;
}

思路2：异或

#include <stdio.h>
int main()
{
    int x = 3;
    int y = 2;
    x = x ^ y;
    y = x ^ y;
    x = x ^ y;
    printf("%d,%d\n", x, y);
    return 0;
}

运行结果如下：