链表反转

示例程序：

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

typedef struct node* link;
struct node
{
	int item;
	link next;
};


//链表倒置
link reverse(link x)
{
	//保存y的下一个选项
	link t;
	link r = NULL;
	link y = x;

	while(y != NULL)
	{
		//保存y的next
		t = y->next;
		//改变方向
		y->next = r ;
		//向后面平移两个指针
		r = y;
		y = t;
	}
	return r;
}


int main()
{
	int N;  

	int i;

	scanf("%d",&N);

	link head = (link)malloc(sizeof(*head));
	head->item = 1;

	link tmp = head;


	for(i = 2;i <= N;i++)
	{
		link temp = (link)malloc(sizeof(*temp));
		temp->item = i;
		temp->next = NULL;

		tmp->next = temp;
		tmp = temp;
	}
	head = reverse(head);
	
	//第二个条件是tmp != NULL
	for(tmp = head;tmp != NULL;tmp = tmp->next)
	{
		printf("%d ",tmp->item);
	}

	return 0;
}