双向链表的创建查找与删除元素

双向链表也叫双链表，是链表的一种，它的每个数据结点中都有两个指针，分别指向直接后继和直接前驱。所以，从双向链表中的任意一个结点开始，都可以很方便地访问它的前驱结点和后继结点。一般我们都构造双向循环链表。

#include <stdio.h>
#include <stdlib.h>
#define ERROR printf("ERROR");
#define MAXSIZE 20
#define YES "yes"

typedef struct student {
    char name[MAXSIZE];
    struct student *Prior,*Next;
}Node,*LinkList;

struct student *CreatList(int n){
    int i;
    LinkList p1,p2,head;

    head = (LinkList)malloc(sizeof(Node));
    head->name[0] = '0';
    head->Prior = NULL;
    head->Next = NULL;
    p2 = head;
    printf("Please input the intenger array:\n");

    for(i=0;i<n;i++){
        p1 = (LinkList)malloc(sizeof(Node));

        scanf("%s",p1->name);

        p2->Next = p1;

        p1->Prior = p2;
        p1->Next = NULL; 
        p2 = p1; 
        }

    p1->Next = NULL;
    return head;
}

//查找元素 
Node *search(LinkList h,char* E)
{
        LinkList p;
        p = h->Next;

        while(p){
            if(!(strcmp(p->name,E)))
                return p;
            else
                p = p->Next;
        }ERROR
        return 0;
} 

void ElementDelete(LinkList pt)
{
    /*方法1： 
    LinkList qt;
    qt = pt->Prior;
    pt = qt->Next;
    qt->Next = pt->Next;
    free(pt);*/ 

    //方法2：
    pt->Next->Prior = pt->Prior;
    pt->Prior->Next = pt->Next;
    free(pt);
}

int main(int argc, char *argv[]) {

    int n,name;
    char FindName[MAXSIZE],st[3];
    LinkList p,q,head;

    printf("Please input the chain length:\n");
    scanf("%d",&n);
    head = CreatList(n);
    p = head->Next;
    printf("Now the chain is:\n");
    while(p){
        printf("%s\t",p->name);
        p = p->Next;
    } 
    printf("\n");

    printf("Please enter the name you want to find:\n");
    scanf("%s",FindName);
    q = search(head,FindName);
    if(q){
    printf("已找到：%s\nAre you sure to delete it?('yes'or'no'):\n",q->name);
    }

    scanf("%s",st);
    if(!(strcmp(YES,st))){
        ElementDelete(q);
        p = head->Next;
        printf("Now the chain is:\n");
        while(p){
            printf("%s\t",p->name);
            p = p->Next;
        } 
    }
    else
        printf("Exited");   

    getch();
    return 0;
}