使用C语言实现双向链表的建立、删除和插入

#include<stdio.h>

#include<stdlib.h>

#include<malloc.h>

struct list{

int data

struct list *next

struct list *pre

}

typedef struct list node

typedef node *link

link front=NULL,rear,ptr,head=NULL

link push(int item){

link newnode=(link)malloc(sizeof(node))

newnode->data=item

if(head==NULL)

{

head=newnode

head->next=NULL

head->pre=NULL

rear=head

}

else

{

rear->next=newnode

newnode->pre=rear

newnode->next=NULL

rear=newnode

}

return head

}

void makenull(){

front=NULL

rear=NULL

}

empty(){

if(front==NULL)

return 1

else

return 0

}

int tops(){

if(empty())

return NULL

else

return rear->data

}

void pop(){

if(empty())

printf("stack is empty!\n")

else

rear=rear->pre

}

void display(link l){

link p

p=l

while(p!=NULL){

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

p=p->next

}

}

void main(){

int n,i

printf("input your first data!\n")

scanf("%d",&n)

front=push(n)

/*another data*/

for(i=0i<3i++)

{

printf("input:\n")

scanf("%d",&n)

push(n)

}

ptr=front

display(ptr)

printf("\n Please enter any key to pop")

pop()

ptr=front

display(ptr)

}

#include

#include

#include

typedef struct Node

{

int date

struct Node * pNext

}NODE, *PNODE

//函数声明

PNODE creat_list()//创建链表

void traverse_list(PNODE pHead)//输出链表

void Insert(PNODE pHead,int pos,int e)//pos 为插入位置 e为插入的数据

void Delete(PNODE pHead,int pos,int *e)

//pos 为删除链表第pos个数 e存放被删除的数据

int main()

{

int e

PNODE pHead = NULL

pHead = creat_list()

traverse_list(pHead)

Insert(pHead,2,99)

traverse_list(pHead)

Delete(pHead,3,&e)

printf("被删除的数据为 %d\n",e)

traverse_list(pHead)

return 0

}

PNODE creat_list()

{

int len//用来存放有效结点的个数

int i

int val//用来临时存放有效结点的数据

PNODE pHead = (PNODE)malloc(sizeof(NODE))

//创建一个不存放数据的结点，pHead 为头指针

if (pHead == NULL)

{

printf("内存分配失败，程序终止！\n")

exit(-1)

}

PNODE pTail = pHead

pTail->pNext = NULL

printf("请输入你需要生成的链表的个数：len = ")

scanf("%d",&len)

for (i = 0i <leni++)

{

printf("请输入第%d个节点的值：",i+1)

scanf("%d",&val)

PNODE pNew = (PNODE)malloc(sizeof(NODE))

//当i = 0 时，创建的第一个结点是首结 每创建一个新结点

if (pNew == NULL)

{

printf("内存分配失败，程序终止！\n")

exit(-1)

}

pNew->date = val

pTail->pNext = pNew

pNew->pNext = NULL

pTail = pNew

}

return pHead

}

void traverse_list(PNODE pHead)

{

PNODE p = pHead->pNext

while(NULL != p)

{

printf("%d ",p->date)

p = p->pNext

}

printf("\n")

return

}

void Insert(PNODE pHead,int pos,int e)

{

int j = 0

PNODE p, s

p = pHead

while(p &&j <pos - 1)

{

p = p->pNext

j++

}

if(!p || j >pos - 1)

exit(-1)

s = (PNODE)malloc(sizeof(NODE))

s->date = e

s->pNext = p->pNext

p->pNext = s

}

void Delete(PNODE pHead,int pos,int *e)

{

int j = 0

PNODE p, r

p = pHead

while(p &&j <pos - 1)

{

p = p->pNext

j++

}

if(!p->pNext || j >pos - 1)

exit(-1)

r = p->pNext

p->pNext = r->pNext

*e = r->date

free(r)

}

---