C语言实现双向链表删除节点、插入节点、双向输出等操作

#include<cstdio>

#include<cstdlib>

typedef struct DoubleLinkedList

{

    int data;

    struct DoubleLinkedList *pre;

    struct DoubleLinkedList *next;

}DlinkedList_Node;

//建立链表

DlinkedList_Node* createDLink()

{

    DlinkedList_Node *head,*p,*s;

    int x;

    head = (DlinkedList_Node*)malloc(sizeof(DlinkedList_Node));

    p = head;

    while(1)

    {

        printf("please input the data: \n");

        scanf("%d",&x);

        if(x != 65535)

        {

            s = (DlinkedList_Node*)malloc(sizeof(DlinkedList_Node));

            s ->data = x;

            s-> pre = p;

            p->next = s;

            p=s;

        }

        else

            {

                printf("\n数据输入结束\n");

                break;

            }

    }

    p->next = NULL;

    head = head ->next;

    head->pre = NULL;

    return head;

}

//顺序、反序打印链表

void printDLink(DlinkedList_Node *head)

{

    DlinkedList_Node *p,*s;

    p = head;

    printf("正序输出双向链表：\n");

    while(p)

    {

        printf("%d ",p->data);

        s = p;

        p = p->next;

    }

    printf("\n 逆序输出双向链表: \n");

    while(s)

    {

        printf("%d ",s->data);

        s = s->pre;

    }

    printf("\n \n");

}

//删除一个结点

DlinkedList_Node* deleteDlinkedList_Node(DlinkedList_Node *head,int i)

{

    DlinkedList_Node *p;

    p = head;

    if(p->data == i)

    {

        head = p->next;

        head->pre = NULL;

        free(p);

        return head;

    }

    while(p)

    {

        if(p->data == i)

        {

        p->pre->next = p->next;

        p->next->pre = p->pre;

        free(p);

        return head;

        }

        p = p->next;

    }

    printf("没有找到想要删除的数据\n");

    return head;

}

//插入一个结点

DlinkedList_Node* insertDlinkedList_Node(DlinkedList_Node *head,int i)

{

    DlinkedList_Node *p,*temp;

    p = head;

    temp = (DlinkedList_Node*)malloc(sizeof(DlinkedList_Node));

    temp ->data = i;

    if(i < p->data)//比头结点数据小，插入到链表头部

    {

        head = temp;

        head->next = p;//此处p为原来的head

        head->pre = NULL;

        p->pre = head;//此处p为原来的head

        return head;

    }

    while(p != NULL && i > p->data)//寻找合适的插入位置

    {

        p = p->next;

    }

    if(i < p->data)//在链表中间某处找到合适插入位置

    {

        temp ->next = p;

        temp ->pre = p->pre;

        p ->pre->next = temp;

        p ->pre = temp;

        return head;

    }

    else//没有找到合适的位置，只有将数据插入到链表尾部

    {

        p->next = temp;  //遍历到链表尾部，p==NULL

        temp ->pre = p;

        temp ->next = NULL;

        return head;

    }

}

int main()

{

    DlinkedList_Node *head;

    head = createDLink();

    printDLink(head);

    head = insertDlinkedList_Node(head,1012);

    head = deleteDlinkedList_Node(head,1991);

    printDLink(head);

}

/*****************************

运行结果如下：

please input the data:

1991

please input the data:

1992

please input the data:

2013

please input the data:

2014

please input the data:

512

please input the data:

420

please input the data:

65535



数据输入结束

正序输出双向链表：

1991 1992 2013 2014 512 420

 逆序输出双向链表:

420 512 2014 2013 1992 1991



正序输出双向链表：

1012 1992 2013 2014 512 420

 逆序输出双向链表:

420 512 2014 2013 1992 1012



******************************/