c语言双向链

#include"stdio.h"
#include"malloc.h"
#define NULL 0
struct node
{
    char name[20];
    struct node *next,*prior;
};
struct node *creat(int n)
{
    struct node *h,*p,*s;
    int i;
    h=(struct node*)malloc(sizeof(struct node));
    h->name[0]='\0';
    h->prior=NULL;
    h->next=NULL;
    p=h;
    for(i=0;i<n;i++)
    {
        s=(struct node*)malloc(sizeof(struct node));
        p->next=s;
        printf("Input the %d student's name:",i+1);
        scanf("%s",s->name);
        s->prior=p;
        s->next=NULL;
        p=s;
    }
    p->next=NULL;
    return h;
}
struct node *search(struct node *h,char*x)
{
    struct node *p;
    char *y;
    p=h->next;
    while(p)
    {
        y=p->name;
        if(strcmp(y,x)==0)return p;
        else p=p->next;
    }
    printf("cannot find datd!\n");
}
void del(struct node *p)
{  
    p->next->prior=p->prior;
    p->prior->next=p->next;
    free(p);
}
main()
{
    int number;
    char sname[20];
    struct node *head,*sp;
    puts("Please in put the size of the list;");
    scanf("%d",&number);
    head=creat(number);
    sp=head->next;
    printf("\nNow the double list is:\n");
    while(sp)
    {
        printf("  %s",&*(sp->name));
        sp=sp->next;
    }
    printf("\nPlease input the name which you want to find:\n");
    scanf("%s",sname);
    sp=search(head,sname);
    printf("the name you want to find is: %s\n",*&sp->name);
    del(sp);
    sp=head->next;
    printf("\nNow the double list is:\n");
    while(sp)
    {
        printf("  %s",&*(sp->name));
        sp=sp->next;
    }
    printf("\n");
    puts("\n Press any key to quit...");
    getch();
}求人解释我备注了的地方

#include"stdio.h"
#include"malloc.h"
#define NULL 0
struct node
{
    char name[20];
    struct node *next,*prior;  //定义结构结点指针
};
struct node *creat(int n)
{
    struct node *h,*p,*s;
    int i;
    h=(struct node*)malloc(sizeof(struct node));
    h->name[0]='\0';
    h->prior=NULL;
    h->next=NULL;
    p=h;
    for(i=0;i<n;i++)
    {
    s=(struct node*)malloc(sizeof(struct node));
    p->next=s; // 让指针p所指结点指向s结点，即h结点的下一结点是s
    printf("Input the %d student's name:",i+1);
    scanf("%s",s->name);
    s->prior=p;
    s->next=NULL; //s指向空节点，即s是尾结点
    p=s; //让指针p指向向结点s，此时指针p所指结点编出s
    }
    p->next=NULL;
    return h;
}
struct node *search(struct node *h,char*x)
{
    struct node *p;
    char *y;
    p=h->next;
    while(p)
    {
    y=p->name;
    if(strcmp(y,x)==0)return p;
    else p=p->next;
    }
    printf("cannot find datd!\n");
}
void del(struct node *p)
{  
    p->next->prior=p->prior;//指针p所指结点的下一结点的头结点，指向指针p所指结点的前一节点

    p->prior->next=p->next; // 指针p所指结点的前一节点指向，指针p所指结点的后一节点

//这两步实现将p所指结点，排除到双向链表之外
    free(p); //删除p所指结点
}
main()
{
    int number;
    char sname[20];
    struct node *head,*sp;
    puts("Please in put the size of the list;");
    scanf("%d",&number);
    head=creat(number);
    sp=head->next;
    printf("\nNow the double list is:\n");
    while(sp)
    {
    printf("  %s",&*(sp->name));
    sp=sp->next;
    }
    printf("\nPlease input the name which you want to find:\n");
    scanf("%s",sname);
    sp=search(head,sname);
    printf("the name you want to find is: %s\n",*&sp->name);
    del(sp);
    sp=head->next;
    printf("\nNow the double list is:\n");
    while(sp)
    {
    printf("  %s",&*(sp->name));
    sp=sp->next;
    }
    printf("\n");
    puts("\n Press any key to quit...");
    getch();
}

   h->prior=NULL;    是的

    s->prior=p;    保证每次建立链表的表尾都是空

    p->next->prior=p->prior;
    p->prior->next=p->next;
    free(p);
就是跳过p 把p之前的结点与之后的结点链接起来  然后安全的删除结点p