swap函數的四種寫法

swap 函數的四種寫法

(1)經典型 --- 嫁衣法

void swap(int *a, int *b)
{
	int temp;
	temp = *a;
	*a = *b;
	*b = temp;
}

(2)經典型改進版  --- 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 --- 賦值法

void swap(int *a, int *b)
{
	*a = *a + *b;
	*b = *a - *b;
	*a = *a - *b;
}

(4)詭異型 --- 邏輯運算法

void swap(int *a, int *b)
{
	*a = *a ^ *b;
	*b = *b ^ *a;
	*a = *a ^ *b;
}