//法一（正常方法）
int main()
{int a = 3;int b = 5;int tmp = 0;//临时变量printf("before:a=%d b=%d\n", a, b);tmp = a;a = b;b = tmp;printf("after:a=%d b=%d\n", a, b);return 0;
}
//法二（加减法） 有缺陷 a=a+b超出范围就可能出错（可能会溢出）
int main()
{int a = 3;int b = 5;printf("before:a=%d b=%d\n", a, b);a = a + b;b = a - b;a = a - b;printf("after:a=%d b=%d\n", a, b);return 0;
}
//法三（异或法）
int main()
{int a = 3;int b = 5;printf("before:a=%d b=%d\n", a, b);a = a ^ b;//a 011 b 101 异或结果为110b - a ^ b;a = a ^ b;printf("after:a=%d b=%d\n", a, b);return 0;
}