作者：舊夢(mèng)拾遺186

專欄：數(shù)據(jù)結(jié)構(gòu)成長(zhǎng)日記

?文章來(lái)源地址http://www.zghlxwxcb.cn/news/detail-514000.html

前言：

帶頭雙向循環(huán)鏈表：結(jié)構(gòu)最復(fù)雜，一般用在單獨(dú)存儲(chǔ)數(shù)據(jù)。實(shí)際中使用的鏈表數(shù)據(jù)結(jié)構(gòu)，都是帶頭雙向循環(huán)鏈表。另外這個(gè)結(jié)構(gòu)雖然結(jié)構(gòu)復(fù)雜，但是使用代碼實(shí)現(xiàn)以后會(huì)發(fā)現(xiàn)結(jié)構(gòu)會(huì)帶來(lái)很多優(yōu)勢(shì)，實(shí)現(xiàn)反而簡(jiǎn)單了。
現(xiàn)在我們來(lái)通過(guò)代碼實(shí)現(xiàn)帶頭雙向循環(huán)鏈表，結(jié)構(gòu)上雖然是鏈表最復(fù)雜的，但是并沒(méi)有我們想象的那么困難，恰恰相反，其代碼實(shí)現(xiàn)比較簡(jiǎn)單
?

帶頭雙向鏈表樣例：

?

代碼實(shí)現(xiàn)?

List.h

#pragma once
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <stdbool.h>

typedef int LTDataType;
typedef struct ListNode
{
	struct ListNode* next;
	struct ListNode* prev;
	LTDataType data;
}LTNode;

LTNode* ListInit();

void ListPrint(LTNode* phead);

void ListPushBack(LTNode* phead, LTDataType x);

void ListPushFront(LTNode* phead, LTDataType x);

void ListPopBack(LTNode* phead);

void ListPopFront(LTNode* phead);

bool ListEmpty(LTNode*phead);

size_t ListSize(LTNode*phead);

LTNode* ListFind(LTNode* phead,LTDataType x);

//在pos之前插入
void ListInsert(LTNode* pos, LTDataType x);

//刪除pos位置
void ListErase(LTNode* pos);

void ListDestory(LTNode* phead);

List.c?

#include "List.h"

LTNode* ListInit()
{
	LTNode* guard = (LTNode*)malloc(sizeof(LTNode));
	if (guard == NULL)
	{
		perror("malloc fail");
		exit(-1);
	}
	guard->next = guard;
	guard->prev = guard;
	return guard;
}

LTNode* BuyListNode(LTDataType x)
{
	LTNode* node = (LTNode*)malloc(sizeof(LTNode));
	if (node == NULL)
	{
		perror("malloc fail");
		exit(-1);
	}
	node->next = NULL;
	node->prev = NULL;
	node->data = x;
	return node;
}


void ListPrint(LTNode* phead)
{
	assert(phead);
	printf("phead<=>");
	LTNode* cur = phead->next;
	while (cur != phead)
	{
		printf("%d<=>", cur->data);
		cur = cur->next;
	}
	printf("\n");
}

void ListPushBack(LTNode* phead, LTDataType x)
{
	assert(phead);
	LTNode* newnode = BuyListNode(x);
	LTNode* tail = phead->prev;
	tail->next = newnode;
	newnode->prev = tail;
	newnode->next = phead;
	phead->prev = newnode;
}


void ListPushFront(LTNode* phead, LTDataType x)
{
	assert(phead);
	LTNode* newnode = BuyListNode(x);
	//考慮先后順序
	/*newnode->next = phead->next;
	phead->next->prev = newnode;
	phead->next = newnode;
	newnode->prev = phead;*/
	//記錄下一位，就不用考慮順序
	LTNode* first = phead->next;
	phead->next = newnode;
	newnode->prev = phead;
	newnode->next = first;
	first->prev = newnode;
}



void ListPopBack(LTNode* phead)
{
	assert(phead);
	assert(!ListEmpty(phead));

	LTNode* tail = phead->prev;
	LTNode* prev = tail->prev;
	prev->next = phead;
	phead->prev = prev;
	free(tail);
	tail = NULL;
}

void ListPopFront(LTNode* phead)
{
	assert(phead);
	assert(!ListEmpty(phead));
	LTNode* first = phead->next;
	LTNode* second = first->next;

	phead->next = second;
	second->prev = phead;
	free(first);
	first = NULL;
}


bool ListEmpty(LTNode* phead)
{
	assert(phead);
	return phead->next == phead;
}

size_t ListSize(LTNode*phead)
{
	assert(phead);
	size_t n = 0;
	LTNode* cur = phead->next;
	while (cur != phead)
	{
		++n;
		cur = cur->next;
	}
	return n;
}

LTNode* ListFind(LTNode* phead, int x)
{
	assert(phead);
	size_t n = 0;
	LTNode* cur = phead->next;
	while (cur != phead)
	{
		if (cur->data == x)
		{
			return cur;
		}
	}
	return NULL;
}


//在pos之前插入
void ListInsert(LTNode* pos, LTDataType x)
{
	assert(pos);
	LTNode* prev = pos->prev;
	LTNode* newnode = BuyListNode(x);

	prev->next = newnode;
	newnode->prev = prev;
	newnode->next = pos;
	pos->prev = newnode;
}

//刪除pos位置
void ListErase(LTNode* pos)
{
	assert(pos);
	LTNode* prev = pos->prev;
	LTNode* next = pos->next;

	prev->next = next;
	next->prev = prev;
	free(pos);
}

//可以傳二級(jí)，內(nèi)部置空
//一級(jí)指針外部置空
void ListDestory(LTNode* phead)
{
	assert(phead);
	LTNode* cur = phead->next;
	while (cur != phead)
	{
		LTNode* next = cur->next;
		free(cur);
		cur = next;
	}
	free(phead);
}

?test.c

#include "List.h"

//測(cè)試尾插、頭插、尾刪、打印
void TestList1()
{
	LTNode* plist = ListInit();
	ListPushBack(plist, 1);
	ListPushBack(plist, 2);
	ListPushBack(plist, 3);
	ListPushBack(plist, 4);
	ListPrint(plist);

	ListPushFront(plist, 10);
	ListPushFront(plist, 20);
	ListPushFront(plist, 30);
	ListPushFront(plist, 40);
	ListPrint(plist);

	ListPopBack(plist);
	ListPopBack(plist);
	ListPopBack(plist);
	ListPopBack(plist);
	ListPrint(plist);

	ListPopBack(plist);
	ListPopBack(plist);
	ListPopBack(plist);
	ListPopBack(plist);
	ListPrint(plist);

	ListPopBack(plist);
	ListPrint(plist);

}

//測(cè)試頭刪、銷毀
void TestList2()
{
	LTNode* plist = ListInit();
	ListPushBack(plist, 1);
	ListPushBack(plist, 2);
	ListPushBack(plist, 3);
	ListPushBack(plist, 4);
	ListPrint(plist);

	ListPopFront(plist);
	ListPopFront(plist);
	ListPrint(plist);
	ListPopFront(plist);
	ListPopFront(plist);
	ListPrint(plist);

	ListDestory(plist);
	plist = NULL;
}



int main()
{
	//TestList1();
	TestList2();
	return 0;
}

總結(jié)：

?

?

?

?

結(jié)語(yǔ)：

?鏈表的學(xué)習(xí)結(jié)束啦?。。⊥瑢W(xué)們要時(shí)常復(fù)習(xí)和刷題啊，我也寫(xiě)了好多鏈表的習(xí)題博客，同學(xué)們可以來(lái)訪問(wèn)啦。

?

到了這里，關(guān)于【數(shù)據(jù)結(jié)構(gòu)與算法】雙向鏈表的文章就介紹完了。如果您還想了解更多內(nèi)容，請(qǐng)?jiān)谟疑辖撬阉鱐OY模板網(wǎng)以前的文章或繼續(xù)瀏覽下面的相關(guān)文章，希望大家以后多多支持TOY模板網(wǎng)！