一道TX的笔试题，删除双向链表的一个指定节点

// doubleLink.cpp : 定义控制台应用程序的入口点。
//

/*
给定一个数，从这个双向链表中删除数值为这个数的节点。如果有多个这样的节点，只要删除任意一个即可。
请给出函数原型和代码实现。
*/
/*
带有头结点的双向链表，我删除的是第一个顺序遍历，发现的节点
我实在vs2008下编写的。
*/
#include "stdafx.h"
#include <stdlib.h>
#include <stdio.h>
#include <windows.h>
struct node {
    int value;
    struct node *priv;
    struct node *next;
};
/*建立一个双向链表*/
struct node* create_double_link();
/*删除指定值的双向链表*/
struct node* delete_double_link(struct node* head,int value);
void print_double_link(struct node*  head);

struct node* create_double_link()
{

    struct node* head=NULL;
    struct node* pcurrent=NULL;
    struct node*ptemp=NULL;

    int num=0,total=0;
    do
    {
        printf("please input the number: \n");
        scanf("%d",&total);
        if( total == 0 )
            printf("sorry,the number is error!\n");
        else
            printf("\n");

    }while( total == 0 );

    while(num<total)
    {
        num=num+1;

        pcurrent=(struct node*)malloc(sizeof(struct node));
        if( pcurrent==NULL )
        {
            printf("malloc error,please check it!\n");
            break;
        }
        else
        {
            pcurrent->value=num;
        }

        if( num == 1)
        {
            head=pcurrent;
            pcurrent->priv=NULL;
        }
        else
        {
            ptemp->next=pcurrent;
            pcurrent->priv=ptemp;
        }
        ptemp=pcurrent;
    }
    ptemp->next=NULL;
    return (head);
}

struct node* delete_double_link(struct node* head,int value)
{
    struct node* pcurrent=NULL;
    pcurrent=head;

    if( head==NULL )
    {
        printf("error:please check the data!\n");
        return(NULL);
    }
    else
    {
        while( (value!=pcurrent->value)&&(pcurrent->next!=NULL) )
            pcurrent=pcurrent->next;

        if(value==pcurrent->value)//find it
        {
            if( pcurrent==head )// is head node
            {
                pcurrent->next->priv=NULL;
                head=pcurrent->next;
            }
            else if(pcurrent->next==NULL)//wear
            {
                pcurrent->priv->next=NULL;
            }
            else
            {
                pcurrent->priv->next=pcurrent->next;
                pcurrent->next->priv=pcurrent->priv;
            }

            free(pcurrent);

            printf("the num have been deletea is: %d\n",value);
        }
        else
        {
            printf("can not find the num: %d\n",value);
        }
    }
    return(head);
}
void print_double_link(struct node*  head)
{
    struct node*  ptemp;
    if( head == NULL)
    {
        printf("error:have no data!\n");
        return;
    }
    ptemp=head;
    while(ptemp)
    {
        printf("num: %d\n",ptemp->value);
        ptemp=ptemp->next;
    }
    return;
}
int _tmain(int argc, _TCHAR* argv[])
{

    struct node* head,ptemp;
    int num=0;

    head=create_double_link();
    print_double_link(head);    

    printf("please input the delete num:\n");
    scanf("%d",&num);
    head=delete_double_link(head, num);
    print_double_link(head);
    Sleep(10000);
	return 0;
}