翻转链表

//翻转一个链表
#include <stdio.h>
#include <stdlib.h>

typedef struct LNode{
    int data;
    struct LNode *next;
}LNode,*LinkList;
//创建一个含有n个元素的单链表
LNode *createList(int n){
    LNode *head = NULL,*p1,*p2;
    for(int i=1;i<=n;i++)
    {
        p1 = (LinkList)malloc(sizeof(LNode));
        if(p1==NULL)
            return NULL;
        printf("输入链表中第%d个数",i);
        scanf("%d",&p1->data);
        if(head==NULL)
        {
            head = p1;
            p2 = p1;
        }else
        {
            p2->next = p1;
            p2 = p1;
        }
    }
    p2->next = NULL;
    return head;
}

//打印链表
void printList(LNode *head){
    LNode *p = head;
    while(p!=NULL){
        printf("%d  ",p->data);
        p = p->next;

    }
}
//使用三个指针依次改变节点指向翻转链表
LinkList reverseList(LinkList head)
{
    LinkList pNode = head;   //当前要翻转的节
    LinkList pPre = NULL;    //翻转后当前节点前一个节点
    LinkList pNext = NULL;    //保存翻转前当前节点后一个节点
    LinkList resHead = NULL;   //翻转后链表头节点

    while(pNode != NULL)
    {
        pNext = pNode->next;    
        if(pNext==NULL)
        {
            resHead = pNode;
        }
        pNode->next = pPre;
        pPre = pNode;
        pNode = pNext;
    }

    return resHead;
}

int main(int argc, char *argv[]) {
    //创建顺序链表
    LNode *head1 = createList(5);
    printList(head1);
    printf("\n");
    printList(reverseList(head1));
    printf("\n");
    return 0;
}