单向链表的逆置

#include <stdio.h>
#include <stdlib.h>
#include <string.h>



typedef struct list LIST; 
struct list
{
	int data; 
	struct list *next;
};


void print_list(struct list *p)
{

	struct list *head = p;
	while (head)
	{
		printf("data = %d\n", head->data);
		head = head->next;
	}

}

//单向链表的逆置
void reverse(struct list *p)
{
	if (p == NULL)
		return;

	if (p->next == NULL || p->next->next == NULL)
		return;

	struct list *last = p->next;

	struct list *cur = p->next;
	struct list *pre = p;
	struct list *next = NULL;

	while (cur)
	{
		next = cur->next;
		cur->next = pre;
		pre = cur;
		cur = next;
	}
	p->next = pre; //未逆置前的首节点指向尾节点
	last->next = NULL;
}


int main()
{
	struct list* p1 = calloc(1, sizeof(struct list));
	struct list* p2 = calloc(1, sizeof(struct list));
	struct list* p3 = calloc(1, sizeof(struct list));
	struct list* p4 = calloc(1, sizeof(struct list));
	struct list* p5 = calloc(1, sizeof(struct list));
	p1->data = 1;
	p1->next = p2;

	p2->data = 2;
	p2->next = p3;

	p3->data = 3;
	p3->next = p4;

	p4->data = 4;
	p4->next = p5;

	p5->data = 5;
	p5->next = NULL;

	reverse(p1);
	print_list(p1);

	return 0;
}