数据结构之带头双向循环链表（源代码）

List.h

//带头双向循环链表

#ifndef __LIST_H__
#define __LIST_H__

#include<stdio.h>
#include<stdlib.h>
#include<assert.h>
#include<malloc.h>

typedef int LTDataType;
typedef struct ListNode
{
	LTDataType _data;
	struct ListNode* _next;   //后继
	struct ListNode* _prev;   //前驱
}ListNode;

typedef struct List
{
	ListNode* _head;
}List;

void ListNodeInit(List* plist);
void ListNodeDestory(List* plist);
void ListNodePrint(List* plist);

void ListNodePushBack(List* plist, LTDataType x);
void ListNodePopBack(List* plist);
void ListNodePushFront(List* plist, LTDataType x);
void ListNodePopFront(List* plist);

ListNode* ListFind(List* plist, LTDataType x);
//在pos的前面进行插入
void ListInsert(ListNode* pos, LTDataType x);
//删除pos位置的节点
void ListErase(ListNode* pos);
void ListRemove(List* plist, LTDataType x);

void ReverseList(List* plist);
int ListSize(List* plist);
int ListEmpty(List* plist);

#endif   //__LIST_H__

List.c

#include"List.h"

//构造新节点
ListNode* BuyListNode(LTDataType x)
{
	ListNode* newnode = (ListNode*)malloc(sizeof(ListNode));
	assert(newnode);
	newnode->_data = x;
	newnode->_next = NULL;
	newnode->_prev = NULL;
	return newnode;
}

//初始化链表
void ListNodeInit(List* plist)
{
	assert(plist != NULL);
	ListNode* head = BuyListNode(0);
	head->_next = head;
	head->_prev = head;
	plist->_head = head;
}

//尾插
void ListNodePushBack(List* plist, LTDataType x)
{
	assert(plist != NULL);
	ListNode* newnode = BuyListNode(x);
	ListNode* head = plist->_head;
	ListNode* tail = head->_prev;
	newnode->_prev = tail;
	tail->_next = newnode;
	newnode->_next = head;
	head->_prev = newnode;
}

//尾删
void ListNodePopBack(List* plist)
{
	assert(plist != NULL && plist->_head->_next != plist->_head);
	ListNode* head = plist->_head;
	ListNode* tail = head->_prev;
	ListNode* tailprev = tail->_prev;
	free(tail);
	tail = NULL;
	tailprev->_next = head;
	head->_prev = tailprev;
}

//头插
void ListNodePushFront(List* plist, LTDataType x)
{
	assert(plist != NULL);
	ListNode* newnode = BuyListNode(x);
	ListNode* head = plist->_head;
	ListNode* next = plist->_head->_next;
	head->_next = newnode;
	newnode->_prev = head;
	newnode->_next = next;
	next->_prev = newnode;
}

//头删
void ListNodePopFront(List* plist)
{
	assert(plist != NULL);
	ListNode* head = plist->_head;
	ListNode* next = plist->_head->_next;
	ListNode* nextnext = plist->_head->_next->_next;
	free(next);
	next = NULL;
	head->_next = nextnext;
	nextnext->_prev = head;
}

//查找结点
ListNode* ListFind(List* plist, LTDataType x)
{
	assert(plist != NULL);
	ListNode* cur = plist->_head->_next;
	while (cur != plist->_head)
	{
		if (cur->_data == x)
		{
			return cur;
		}
		else
		{
			cur = cur->_next;
		}
	}
	return NULL;
}

//在pos的前面进行插入
void ListInsert(ListNode* pos, LTDataType x)
{
	assert(pos != NULL);
	ListNode* newnode = BuyListNode(x);
	ListNode* prev = pos->_prev;
	newnode->_prev = prev;
	prev->_next = newnode;
	newnode->_next = pos;
	pos->_prev = newnode;
}

//删除pos位置的节点
void ListErase(ListNode* pos)
{
	assert(pos != NULL);
	ListNode* prev = pos->_prev;
	ListNode* next = pos->_next;
	free(pos);
	pos = NULL;
	prev->_next = next;
	next->_prev = prev;
}

//删除节点
void ListRemove(List* plist, LTDataType x)
{
	assert(plist != NULL);
	ListNode* cur = plist->_head->_next;
	ListNode* prev = NULL;
	ListNode* next = NULL;
	while (cur != plist->_head)
	{
		if (cur->_data == x)
		{
			prev = cur->_prev;
			next = cur->_next;
			free(cur);
			prev->_next = next;
			next->_prev = prev;
			cur = next;
		}
		else
		{
			cur = cur->_next;
		}
	}
}

//反转链表
void ReverseList(List* plist)
{
	assert(plist != NULL);
	ListNode* begin = plist->_head->_next;
	ListNode* end = plist->_head->_prev;
	while (begin != end && begin->_next != end)
	{
		LTDataType tmp = begin->_data;
		begin->_data = end->_data;
		end->_data = tmp;
		begin = begin->_next;
		end = end->_prev;
	}
}

//链表长度
int ListSize(List* plist)
{
	assert(plist != NULL);
	ListNode* cur = plist->_head->_next;
	int count = 0;
	while (cur != plist->_head)
	{
		count++;
		cur = cur->_next;
	}
	return count;
}

//空返回0，非空返回1
int ListEmpty(List* plist)
{
	assert(plist != NULL);
	return (plist->_head->_next == plist->_head ? 0 : 1);
}

//销毁链表
void ListNodeDestory(List* plist)
{
	assert(plist != NULL);
	ListNode* cur = plist->_head->_next;
	while (cur != plist->_head)
	{
		ListNode* next = cur->_next;
		free(cur);
		cur = next;
	}
	free(plist->_head);
	plist->_head = NULL;
}

//打印链表
void ListNodePrint(List* plist)
{
	assert(plist != NULL);
	ListNode* cur = plist->_head->_next;
	printf("<-head->");
	while (cur != plist->_head)
	{
		printf("<-%d->", cur->_data);
		cur = cur->_next;
	}
	printf("\n");
}

来源：CSDN

作者：ZD_012

链接：https://blog.csdn.net/ZD_012/article/details/104116058