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   
#include   
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 
 
******************************/