链表翻转

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


struct Node 
{
int value;
struct Node *next;
};


 struct Node * reverse(struct Node *head)
 {
if(!head)
return NULL;
    struct Node *pt = head;
    struct Node *p;
while( pt->next)
    {
p=pt->next;
pt->next = p->next;
p->next = head;
head = p;
     }
return head;
 }


 struct Node * insert(struct Node *head, struct Node *node)
 {
if(!head)
return node;
if(!node)
return NULL;
node->next = head;
head = node;
return head;
 }


 void print(struct Node *node)
 {
if(!node)
return;
while(node) 
{
printf("%d ", node->value);
node = node->next;
}
printf("\n");
 }


int main()
{
struct Node *head = NULL, *node;
int i;
for(i = 0; i < 10; i++)
{
node = (struct Node *)malloc(sizeof(*node));
if(!node)
return -1;
node->next = NULL;
node ->value = i;
head = insert(head, node);
}
print(head);
head = reverse(head);
print(head);
head = reverse(head);
print(head);
return 0;
}