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

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