C单链表实现

/*
 * LinkNode.c
 *
 *  Created on: Jan 14, 2014
 *      Author: root
 */
#include <stdlib.h>
#include <stdio.h>
#include <malloc.h>
typedef struct node
{
    char *data;
    struct node *next;
}Node,*pNode;

pNode create();
void printList(pNode pHead);
int InsertNode(pNode pHead,int front,char *data);
char* DeleteNode(pNode pHead,int pos);
int LengthList(pNode pHead);
void Sort_List(pNode pHead);
pNode Reverse_List(pNode pHead);
int main()
{

    pNode pHead = NULL;
    int front;
    int choose;
    char* return_val=NULL;
    pHead=create();
    printf("你输入的数据是,\n");
    int length;
    length = LengthList(pHead);
    printf("(长度为%d的单链表):\n",length);
    printList(pHead);
    while(1)
    {
    printf("是否还要进行如下操作：\n");
    printf("1.插入数据      2.删除数据     3.修改数据     4.链表排序   5.链表逆序   6.退出\n");
    scanf("%d",&choose);
    if(choose!=1&&choose!=2&&choose!=3&&choose!=4&&choose!=5)
    {
        printf("error:请输入正确的数字!\n");
        break;
    }
    switch(choose)
    {
        case 1:
        {
            printf("请输入要在第几个节点前插入数据：");
            scanf("%d",&front);
            if(front>length)
            {
                front = length;
                printf("Warning:输入结点位置大于链表长度，默认在表尾部添加!\n");
            }
            printf("请输入要插入的数据：");
            char *data = (char*)malloc(sizeof(char*));
            scanf("%s",data);
            if(InsertNode(pHead,front,data)==1)
            {
                 printf("插入成功\n插入后的数据是：\n");
                 printList(pHead);
            }else
            {
                 printf("插入失败\n");
            }
                break;
        }
        case 2:
        {
            printf("请输入要删除第几个节点的数据：");
            scanf("%d",&front);
            if(front>length)
            {
                front=length;
                printf("Warning:输入结点位置大于链表长度，默认删除表最后一个结点!\n");
            }
            return_val = DeleteNode(pHead,front);
            if(return_val==NULL)
            {
                  printf("删除失败。\n");
            }else
            {
                 printf("删除成功。删除的元素是：%s\n",return_val);
            }
                 printf("操作完成后的数据是：\n");
                 printList(pHead);
                 break;
        }
        case 3:
        {
            printf("暂时没有做这个功能!\n");
            break;
        }
        case 4:
        {
            Sort_List(pHead);
            break;
        }
        case 5:
        {
            Reverse_List(pHead);
            break;
        }
        case 6:
        {
            exit(1);
        }
        return 0;
    }

    }

    return 0;
}

pNode create()
{
    int i;
    int len;
    pNode pHead = (pNode)malloc(sizeof(struct node));
    pNode pTail = pHead;
    pTail->next = NULL;
    printf("请输入节点个数：");
    scanf("%d",&len);
    for(i=0;i<len;i++)
    {
        char *val=(char*)malloc(sizeof(char*));//Warning.malloc
        printf("第 %d 个节点的数值：",i+1);
        scanf("%s",val);
        pNode pNew = (pNode)malloc(sizeof(Node));
        pNew->data = val;
        /*
         *  有序的
         *  1.将尾节点的next指针指向新节点
         *  2.然后把新节点next指针设置为空
         *  3. 最后将新节点作为尾节点
         */
        pTail->next=pNew;
        pNew->next=NULL;
        pTail = pNew;
    }
    printf("create list success!");
    return pHead;
}


void printList(pNode pHead)
{
    pNode p = pHead->next;
    while(p!=NULL)
    {
        printf("%s\n",p->data);
        p=p->next;
    }
    printf("\n");
}
int InsertNode(pNode pHead,int front,char *data)
{
    int i = 0;
    pNode _node = pHead;
    pNode pSwap ;

    if((front<1) || (_node==NULL))
    {
        printf("error:List is NULL or front<1");
        return -1;

    }
    while(i<front-1)
    {
        _node = _node->next;
        ++i;
    }
    pNode pNew = (pNode)malloc(sizeof(Node));

    pNew->data=data;
    pSwap = _node->next;
    _node->next = pNew;
    pNew->next = pSwap;

    return 1;
}

char* DeleteNode(pNode pHead,int pos)
{
    int i=0;
    char *data;
    pNode _node =pHead;
    pNode pSwap ;
    if((pos < 1) && (NULL == _node->next))
        {
            printf("failed to delete ! \n");
            return 0;
        }
    while(i < pos-1)
    {
        _node = _node->next;
        ++i;
    }
    pSwap = _node->next;
    data = pSwap->data;
    _node->next = _node->next->next;
    free(pSwap);
    return data;
}

int LengthList(pNode pHead)
{
    int length = 0;
    pNode temp = pHead->next;
    while(temp!=NULL)
    {
        temp=temp->next;
        length++;
    }
    return length;
}

void Sort_List(pNode pHead)
{
    int i , j;
    char* swap ;
    int len=LengthList(pHead);
    pNode m,n;
    for(i=0,m=pHead->next;i<len-1;i++,m=m->next)
    {
        for(j=i+1,n=m->next;j<len;j++,n=n->next)
        {
            if(m->data > n->data)
            {
                swap = m->data;
                m->data = n->data;
                n->data = swap;
            }
        }
    }
    printf("排序完后结果为：\n");
    printList(pHead);
}
pNode Reverse_List(pNode pHead)
{
    if(pHead->next==NULL || pHead->next->next ==NULL)
    {
        return pHead;
    }
    pNode t=NULL;
    pNode p=pHead->next;// first element
    pNode q=pHead->next->next;//second element

    while(q!=NULL)
    {
        t = q->next;
        q->next = p;
        p=q;
        q=t;
    }
    pHead->next->next = NULL;
    pHead->next = p;
    printf("逆序后结果为：\n");
    printList(pHead);
    return pHead;

}