双向链表的学习

最新推荐文章于 2024-08-08 19:57:17 发布

甜菊

最新推荐文章于 2024-08-08 19:57:17 发布

阅读量889

点赞数 3

CC 4.0 BY-SA版权

文章标签：链表数据结构散列表

本文链接：https://blog.youkuaiyun.com/m0_63882760/article/details/124548014

这篇博客详细介绍了双向链表的概念，并提供了C语言实现的基本操作，包括定义、初始化、头插法和尾插法建立链表、求链表长度、打印链表、插入元素、获取元素、定位元素、删除元素等。此外，还展示了完整的代码示例及运行展示，帮助读者理解和掌握双向链表的操作技巧。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

一.概念

二.基本操作

1.定义

//定义双向链表
typedef struct DoubleLinkedNode{
	int data;
	struct DoubleLinkedNode *previous;
	struct DoubleLinkedNode *next;
}DLnode,*Dlinklist;

2.初始化

Dlinklist Initialist()
{
	Dlinklist tempHeader=(Dlinklist)malloc(sizeof(DLnode));
	tempHeader->next=NULL;
	tempHeader->previous=NULL;
	return tempHeader;
}

3.头插法建立双链表

Dlinklist create_head(Dlinklist tempHeader,int n)
{

	tempHeader=(Dlinklist)malloc(sizeof(DLnode));
	tempHeader->previous=NULL;
	tempHeader->next=NULL;
	Dlinklist r;
	r=tempHeader;
	DLnode *p;
	int i;
	for(i=0;i<n;i++)
	{
		p=(DLnode*)malloc(sizeof(DLnode));
		scanf("%d",&p->data);
		if(r->next==NULL)
		{
			r->next=p;
			p->previous=r;
			p->next=NULL;
		}
		else{
		//一上一下 ，先上后下 
		p->previous=r;
		r->next->previous=p;
		p->next=r->next;
		r->next=p;
	    }
   }
	return tempHeader;
}

4.尾插法建立双向链表

Dlinklist create_tail(Dlinklist tempHeader,int n)
{
	tempHeader=(Dlinklist)malloc(sizeof(DLnode));
	DLnode *r,*q;
	r=tempHeader;
	tempHeader->previous=NULL;
	tempHeader->next=NULL;
	int i;
	for(i=0;i<n;i++)
	{
		q=(DLnode*)malloc(sizeof(DLnode));
		scanf("%d",&q->data);
		r->next=q;
		q->previous=r;
		r=q;
	}
	r->next=NULL;
	return tempHeader;
}

5.求链表长度

int Lengthlist(Dlinklist paraHeader)
{
	DLnode *p;
	int i=0;
	p=paraHeader->next;
	while(p)
	{
		i++;
		p=p->next;
	}
	return i;
 }

6.打印链表

//双向链表打印
void Print(Dlinklist tempHeader)
{
	DLnode *p;
	p=tempHeader->next;
	while(p)
	{
		printf("%5d",p->data);
		p=p->next;
	}
	printf("\n");
}

7.在第i个位置插入元素

Dlinklist Insertlist(Dlinklist tempHeader,int i,int e)
 {
 	int j=0;
 	DLnode *p,*s,*r;
 	p=tempHeader;
 	for(j=0;j<i-1;j++)
 	{
 		p=p->next;
 		j++;
    }
    if(!p||j>i-1)
	 {
	 	printf("The position %d is beyond the scope of the list",i);
	 	return;
	 }//判断条件写在外面 
	 r=p->next;
	 s=(DLnode*)malloc(sizeof(DLnode));
	 s->data=e;
 	 s->previous=p;
 	 p->next->previous=s;
 	 s->next=p->next;
 	 p->next=s;
 	 
 	 return tempHeader;
 }

8获取第i个位置的元素

int Getelem(Dlinklist tempHeader,int i)
 {
 	int j;
 	int elem;
 	DLnode *p;
 	p=tempHeader->next;
 	for(j=1;j<i;j++)//找到第i个位置 
 	{
 		p=p->next;
	 }
	 if (!p||j>i)
	 return 0;
	 
	 else
	 {
	 	elem=p->data;
	 }
	 return elem;
  }

9.获取元素e的地址或位置序号

//找到元素e的位置（返回地址或位置序号）
 DLnode *LocateElem(Dlinklist tempHeader,int e)
 {
 	DLnode *p;
 	p=tempHeader->next;
 	while(p&&p->data!=e)
 	{
 		p=p->next;
	 }
	 return p;//查找失败返回NULL 
  } 
  int LOcateelem(Dlinklist tempHeader,int e)
  {
  	DLnode *p;
  	p=tempHeader->next;
  	int i;
  	for(i=1;p&&p->data!=e;i++)
  	{
  		p=p->next;
    }
    if(p)
	return i;
	else
	return 0;//查找失败 
  }
int Lengthlist(Dlinklist paraHeader)
{
	DLnode *p;
	int i=0;
	p=paraHeader->next;
	while(p)
	{
		i++;
		p=p->next;
	}
	return i;
 }

10.删除元素

//删除第position个位置的元素 
Dlinklist deletelist(Dlinklist tempHeader,int position)
{
	DLnode *p;
	int i;
	p=tempHeader;
	for(i=0;i<position;i++)
	{
		p=p->next;
	}
	if(!(p->next)||i>position)
	printf("could not find the elem\n");//find position
	int e=p->data;
	p->previous->next=p->next;
	p->next->previous=p->previous;
	free(p);
	return tempHeader;
}

三.完整代码

#include <stdio.h>
#include <stdlib.h>
//定义双向链表
typedef struct DoubleLinkedNode{
	int data;
	struct DoubleLinkedNode *previous;
	struct DoubleLinkedNode *next;
}DLnode,*Dlinklist; 

Dlinklist Initialist()
{
	Dlinklist tempHeader=(Dlinklist)malloc(sizeof(DLnode));
	tempHeader->next=NULL;
	tempHeader->previous=NULL;
	return tempHeader;
}
//链表头插结点 
Dlinklist create_head(Dlinklist tempHeader,int n)
{

	tempHeader=(Dlinklist)malloc(sizeof(DLnode));
	tempHeader->previous=NULL;
	tempHeader->next=NULL;
	Dlinklist r;
	r=tempHeader;
	DLnode *p;
	int i;
	for(i=0;i<n;i++)
	{
		p=(DLnode*)malloc(sizeof(DLnode));
		scanf("%d",&p->data);
		if(r->next==NULL)
		{
			r->next=p;
			p->previous=r;
			p->next=NULL;
		}
		else{
		//一上一下 ，先上后下 
		p->previous=r;
		r->next->previous=p;
		p->next=r->next;
		r->next=p;
	    }
   }
	return tempHeader;
}
//链表尾插结点 
Dlinklist create_tail(Dlinklist tempHeader,int n)
{
	tempHeader=(Dlinklist)malloc(sizeof(DLnode));
	DLnode *r,*q;
	r=tempHeader;
	tempHeader->previous=NULL;
	tempHeader->next=NULL;
	int i;
	for(i=0;i<n;i++)
	{
		q=(DLnode*)malloc(sizeof(DLnode));
		scanf("%d",&q->data);
		r->next=q;
		q->previous=r;
		r=q;
	}
	r->next=NULL;
	return tempHeader;
}
//双向链表打印
void Print(Dlinklist tempHeader)
{
	DLnode *p;
	p=tempHeader->next;
	while(p)
	{
		printf("%5d",p->data);
		p=p->next;
	}
	printf("\n");
}
Dlinklist Insertlist(Dlinklist tempHeader,int i,int e)
 {
 	int j=0;
 	DLnode *p,*s,*r;
 	p=tempHeader;
 	for(j=0;j<i-1;j++)
 	{
 		p=p->next;
 		j++;
    }
    if(!p||j>i-1)
	 {
	 	printf("The position %d is beyond the scope of the list",i);
	 	return;
	 }//判断条件写在外面 
	 r=p->next;
	 s=(DLnode*)malloc(sizeof(DLnode));
	 s->data=e;
 	 s->previous=p;
 	 p->next->previous=s;
 	 s->next=p->next;
 	 p->next=s;
 	 
 	 return tempHeader;
 }
 int Getelem(Dlinklist tempHeader,int i)
 {
 	int j;
 	int elem;
 	DLnode *p;
 	p=tempHeader->next;
 	for(j=1;j<i;j++)//找到第i个位置 
 	{
 		p=p->next;
	 }
	 if (!p||j>i)
	 return 0;
	 
	 else
	 {
	 	elem=p->data;
	 }
	 return elem;
  } 
  //找到元素e的位置（返回地址或位置序号）
 DLnode *LocateElem(Dlinklist tempHeader,int e)
 {
 	DLnode *p;
 	p=tempHeader->next;
 	while(p&&p->data!=e)
 	{
 		p=p->next;
	 }
	 return p;//查找失败返回NULL 
  } 
  int LOcateelem(Dlinklist tempHeader,int e)
  {
  	DLnode *p;
  	p=tempHeader->next;
  	int i;
  	for(i=1;p&&p->data!=e;i++)
  	{
  		p=p->next;
    }
    if(p)
	return i;
	else
	return 0;//查找失败 
  }
int Lengthlist(Dlinklist paraHeader)
{
	DLnode *p;
	int i=0;
	p=paraHeader->next;
	while(p)
	{
		i++;
		p=p->next;
	}
	return i;
 } 
 //删除第position个位置的元素 
Dlinklist deletelist(Dlinklist tempHeader,int position)
{
	DLnode *p;
	int i;
	p=tempHeader;
	for(i=0;i<position;i++)
	{
		p=p->next;
	}
	if(!(p->next)||i>position)
	printf("could not find the elem\n");//find position
	int e=p->data;
	p->previous->next=p->next;
	p->next->previous=p->previous;
	free(p);
	return tempHeader;
}
   
int main()
{
	int n;
	printf("Please print the length\n");
	scanf("%d",&n);
	Dlinklist tempHeader,paraHeader;
	tempHeader=Initialist();
	tempHeader=create_head(tempHeader,n);
	Print(tempHeader);
	paraHeader=Initialist();
	paraHeader=create_tail(tempHeader,n);
	Print(paraHeader);
	printf("Print the location and elem you want to insert\n");
	int position,e;
	Dlinklist L;
	scanf("%d%d",&position,&e);
	L=Insertlist(paraHeader,position,e);
    printf("THe new list is \n");
    if(L)
    {
    Print(L);
    }
    int place;
    printf("Print the place you want to find\n");
    scanf("%d",&place);
    int result_1;
    result_1=Getelem(L,place);
    if(result_1)
    printf("THe elem is %d\n",result_1);
    DLnode *f;
    int elem1;
    printf("print the elem you want to select\n");
    scanf("%d",&elem1);
    f=LocateElem(L, elem1);
    if(f)
    printf("THe address is 	%p\n",f);
    else
    printf("could not find	\n");
    int result_2;
    result_2=LOcateelem(L,elem1);
    if(result_2)
    printf("THe location is %d\n",result_2);
    else
    printf("could not find\n");
	int result_3=Lengthlist(L);
	printf("THe length is %d\n",result_3);
	int po;
	printf("Print the position you want to delete\n");
	scanf("%d",&po);
	L=deletelist(L,po);
	printf("THe new list is %d:\n");
	Print(L);
	return 0;
}

四.运行展示