2月4日作业

news2024/11/19 7:41:16

1.请编程实现双向链表的头插，头删、尾插、尾删

头插：

尾插：

头删：

尾删：

2.请编程实现双向链表按任意位置插入、删除、修改、查找

插入：

删除：

查找：

修改：

头文件：


#ifndef __HEAD_H_
#define __HEAD_H_

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
typedef int datatype;
enum {FALSE=-1,SUCCESS};
typedef struct node
{
	datatype data;
	struct node *next;
	struct node *prev;
}*doublelink;


doublelink creat();
doublelink insert_head(doublelink head,datatype element);
doublelink insert_rear(doublelink head,datatype element);
void output(doublelink head);
doublelink delete_head(doublelink head);
doublelink delete_rear(doublelink head);
doublelink insert_pos(doublelink head,int pos,datatype element);
doublelink delete_pos(doublelink head,int pos);

datatype search_pos(doublelink head,int pos);
void update_pos(doublelink head,int pos,datatype element);

#endif

主函数：

#include"head.h"

int main(int argc, const char *argv[])
{

	doublelink head=NULL;
	int n;
	printf("please enter n:");
	scanf("%d",&n);
	datatype element;
	for(int i=0;i<n;i++)
	{
		printf("please enter %d element:",i+1);
		scanf("%d",&element); 
		//头插
//		head=insert_head(head,element);
		//尾插
		head=insert_rear(head,element);
		
	}

	//遍历输出
	output(head);
	//头删
//	head=delete_head(head);
//	output(head);
	
	//尾删
//	head=delete_rear(head);
//	output(head);

	//任意位置插入
	int pos;
	printf("please enter pos:");
	scanf("%d",&pos);
	printf("please enter element:");
	scanf("%d",&element);
//	head=insert_pos(head,pos,element);
//	output(head);

	//任意位置删除
//	head=delete_pos(head,pos);
//	output(head);

	//任意位置查找
//	datatype s=search_pos(head,pos);
//	if(s==-1)
//		puts("no");
//	else
//		printf("s=%d\n",s);

	//任意位置修改
	update_pos(head,pos,element);
	output(head);




	return 0;
}

自定义函数：


#include"head.h"
//创建节点
doublelink creat()
{
	doublelink head=(doublelink)malloc(sizeof(struct node));
	if(head==NULL)
		return NULL;
	head->data=0;
	head->next=head->prev=NULL;
	return head;
}

//头插
doublelink insert_head(doublelink head,datatype element)
{
	doublelink s=creat();
	s->data=element;

	if(head==NULL)
	{
		head=s;
	}
	else
	{
		s->next=head;
		head->prev=s;
		head=s;
	}	
	return head;
}

//尾插
doublelink insert_rear(doublelink head,datatype element)
{
	doublelink s=creat();
	s->data=element;
	if(NULL==head)
		head=s;
	else
	{
		doublelink p=head;
		while(p->next!=NULL)
		{
			p=p->next;
		}
		p->next=s;
		s->prev=p;
	}
	return head;
}

//输出
void output(doublelink head)
{
	if(head==NULL)
	{
		printf("empty\n");
		return;
	}
	doublelink p=head;
	while(p->next)
	{
		printf("%-4d",p->data);
		p=p->next;
	}
	printf("%-4d\n",p->data);
}

//头删
doublelink delete_head(doublelink head)
{
	if(head==NULL)
		return head;
/*	if(head->next==NULL)
	{
		free(head);
		head=NULL;
		return head;
	}
*/
	doublelink del=head;
	head=head->next;
	head->prev=NULL;
	free(del);
	del=NULL;
	return head;
}

//尾删
doublelink delete_rear(doublelink head)
{
	if(head==NULL)
		return head;
	if(head->next==NULL)
	{
		free(head);
		head=NULL;
		return head;
	}
	doublelink p=head;
	while(p->next)
	{
		p=p->next;
	}
	p->prev->next=NULL;
	free(p);
	p=NULL;
	return head;
}

//计算长度

int length(doublelink head)
{
	int len=0;
	doublelink p=head;
	while(p)
	{
		len++;
		p=p->next;
	}
	return len;
}

/*
 * function:    任意位置插入
 * @param [ in] 
 * @param [out] 头，位置,插入元素
 * @return      头
 */
doublelink insert_pos(doublelink head,int pos,datatype element)
{
	if(pos==1)
	{
		head=insert_head(head,element);
		return head;
	}
	else if(pos>1 || pos<=length(head))
	{
		doublelink s=creat();
		s->data=element;
		doublelink p=head;
		for(int i=1;i<pos-1;i++)
		{
			p=p->next;
		}
		s->next=p->next;
		s->prev=p;
		p->next->prev=s;
		p->next=s;
		return head;
	}
	else if(pos==length(head)+1)
	{
		head=insert_rear(head,element);
		return head;
	}
	else
	{
		puts("error");
		return head;
	}

}

//任意位置删除

doublelink delete_pos(doublelink head,int pos)
{
	if(head==NULL || pos<1 || pos>length(head))
	{
		puts("error");
		return head;
	}
	if(pos==1)
	{
		head=delete_head(head);
	}
	else if(pos>1 && pos<length(head))
	{
		doublelink p=head;
		doublelink del=head;
		for(int i=1;i<pos-1;i++)
		{
			p=p->next;
		}
		del=p->next;
		p->next=del->next;
		del->next->prev=p;
		free(del);
		del=NULL;
		return head;
	}
	else if(pos==length(head))
	{
		head=delete_rear(head);
		return head;
	}
}

//任意位置查找
datatype search_pos(doublelink head,int pos)
{
	if(head==NULL || pos<1 || pos>length(head))
	{
		return FALSE;
	}
	doublelink p=head;
	int i=1;
	for(i;i<pos;i++)
	{
		p=p->next;
	}
	return p->data;
}

//任意位置修改
void update_pos(doublelink head,int pos,datatype element)
{
	if(head==NULL || pos<1 || pos>length(head))
	{
		puts("error");
		return;
	}
	doublelink p=head;
	int i=1;
	for(i;i<pos;i++)
	{
		p=p->next;
	}
	p->data=element;
}