swap 函数的四种写法

(1)经典型 --- 嫁衣法

void swap(int *a, int *b)

{

	int temp;

	temp = *a;

	*a = *b;

	*b = temp;

}

(2)经典型改进版  --- 泛型法

void swap(void *a, void *b, size_t size)

{

	unsigned char *p = (unsigned char *)a;

	unsigned char *q = (unsigned char *)b;

	unsigned char temp;

	while(size--)

	{

		temp = *p;

		*p = *q;

		*q = temp;

		p ++;

		q ++;

	}

}

(3)取巧型 --- 赋值法

void swap(int *a, int *b)

{

	*a = *a + *b;

	*b = *a - *b;

	*a = *a - *b;

}

(4)诡异型 --- 逻辑运算法

void swap(int *a, int *b)

{

	*a = *a ^ *b;

	*b = *b ^ *a;

	*a = *a ^ *b;

}