C练习——不创建临时变量，交换两个数值

// int 型数值有上限，a+b可能超范围
#include <stdio.h>
int main()
{
    int a = 2;
    int b = 3;
    printf("交换前：%d %d\n", a, b);
    a = a + b; //3+2
    b = a - b; //3+2-3
    a = a - b; //3+2-2
    printf("交换后：%d %d\n", a, b);
    return 0;
}

#include <stdio.h>
int main()
{
    int a = 2;
    int b = 3;
    printf("交换前：%d %d\n", a, b);
    a = a ^ b; //3^2
    b = a ^ b; //3^2^3
    a = a ^ b; //3^2^2
    printf("交换后：%d %d\n", a, b);
    return 0;
}