文章目录

• 我的代码
• 老师的代码

我的代码

// d_list.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
//
 
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
 
struct _d_list
{
	int data;
	struct _d_list *pre;
	struct _d_list *next;
};
 
typedef struct _d_list DL_LINK_LIST;
 
 
void init_d_list_node(DL_LINK_LIST * node, const int data)
{
	node->data = data;
	node->pre = NULL;
	node->next = NULL;
}
 
 
 
//从头添加
//添加至表头 将新数据元素添加到表头，只需要将该元素与表头元素建立双层逻辑关系即可。
//
//换句话说，假设新元素节点为 temp，表头节点为 head，则需要做以下 2 步操作即可：
//
//temp->next = head; head->prior = temp;
//将 head 移至 temp，重新指向新的表头；
 
DL_LINK_LIST * _d_list_add_head(DL_LINK_LIST *head, int data)
{
	if (head == NULL)
	{
		printf("@_d_list_add_head, param head is null, can not trans continue!\n");
		return head;
	}
 
	// 创建节点
	DL_LINK_LIST *node = (DL_LINK_LIST *)malloc(sizeof(DL_LINK_LIST));
	if (NULL == node)
	{
		printf("Not enogh memory to get!\n");
		return head;
	}
 
	init_d_list_node(node, data);
 
	printf("@_d_list_add_head---->try to add %d.\n", data);
	// 从头结点添加
	node->next = head;	// 新节点作为头  那么新节next就是目前的head node->next  = head;
	head->pre = node;	// 当前head的上一个节点pre就是新节点
	head = node;	// 链接完成后 记录新的head
 
	return head;
}
 
 
 
// 从尾部添加
DL_LINK_LIST * _d_list_add_tail(DL_LINK_LIST *head, int data)
{
	printf("@_d_list_add_tail---->try to add %d.\n", data);
	if (head == NULL)
	{
		printf("@_d_list_add_tail, param head is null, can not trans continue!\n");
		return head;
	}
 
	// 创建节点
	DL_LINK_LIST *node = (DL_LINK_LIST *)malloc(sizeof(DL_LINK_LIST));
	if (NULL == node)
	{
		printf("Not enogh memory to get!");
		return head;
	}
 
	init_d_list_node(node, data);
 
	// 找到链表的最后一个元素
	DL_LINK_LIST *p = head;
	while (p->next != NULL)
	{
		p = p->next;
	}
 
	// add
	p->next = node;
	node->pre = p;
 
	return head;
}
 
 
bool _d_list_insert_mid(DL_LINK_LIST * p, int data)
{
	// p为根据条件找到的p->data >= data 的中间节点  新节点要插入在p之前
	if (p == NULL)
	{
		printf("@_d_list_insert_mid, param in node is NULL, can not do insert\n");
		return false;
	}
 
	// 创建节点
	DL_LINK_LIST *node = (DL_LINK_LIST *)malloc(sizeof(DL_LINK_LIST));
	if (NULL == node)
	{
		printf("Not enogh memory to get!");
		return false;
	}
	init_d_list_node(node, data);
 
	// 如果找到了  p->data >= data    node 在p前面  因此节点关系为  
	/*
		pre	---------> p--------->
			<----------
			left<--node -->right
			node 的pre指向pre
			node的next 指向p
			以p来标识
	*/
 
	printf("@_d_list_insert_mid---->try to insert %d.\n", data);
	node->pre = p->pre;	// 1. 连接前节点pre与新增节点node  以p标识前节点为  p->pre  因此  node->pre = p->pre
	node->pre->next = node;	//  2.前节点的next  连接到node   因此  标识为   node->pre->next = node;
	node->next = p;		// 3.连接 node与p 
	p->pre = node;	// 4.p的前节点为新增node
 
	return true;
}
 
// 以升序排序的案例为例子 插入到指定节点
// 从尾部添加
DL_LINK_LIST * _d_list_insert_by_data(DL_LINK_LIST *head, int data)
{
	if (head == NULL)
	{
		printf("@_d_list_insert_by_data, param head is null, can not trans continue!\n");
		return head;
	}
	
 
	DL_LINK_LIST *p = head;
	while (p->next != NULL &&(p->data <data))//  要保证p不能为NULL 因此判断条件为p->next != NULL
	{
		p = p->next;
	}
	printf("@_d_list_insert_by_data---->try to insert %d.\n", data);
 
	if (p->data >= data)
	{
		// 如果插入头结点之前
		if (p == head)
		{
			head = _d_list_add_head(head, data);
		}
		else
		{
			// 找到在中间  按照中间法插入   head 不变
			 (void)_d_list_insert_mid(p, data);
		}
	}
	else
	{
		// 未找到比data大的数据  添加在末尾
		printf("@_d_list_insert_by_data---->未找到比data大的数据  添加在末尾 try to insert %d.\n", data);
		head = _d_list_add_tail(head, data);
	}
 
	return head;
}
 
 
 
DL_LINK_LIST * _d_list_del_head(DL_LINK_LIST *head)
{
	if (head == NULL)
	{
		printf("@_d_list_del_head, the list head is NULL!\n");
		return head;
	}
 
	// 删除头节点
	DL_LINK_LIST *p = head;
	head = head->next;	// 将head后移
	if (head != NULL)
	{
		head->pre = NULL;
	}
	
 
	free(p);
	p = NULL;
 
	return head;
}
 
DL_LINK_LIST * _d_list_del_tail(DL_LINK_LIST *head)
{
	if (head == NULL)
	{
		printf("@_d_list_del_tail, the list head is NULL!\n");
		return head;
	}
 
	DL_LINK_LIST *p = head;
	while (p->next != NULL)
	{
		p = p->next;
	}
 
	// 删除尾节点p p为尾结点  上一个可能是头结点 头结点pre 为NULL
	if (p->pre != NULL)
	{
		p->pre->next = NULL;	// 尾节点的上一个节点next指向空
	}
	
	if (p == head)
	{
		//如果当前删除的是head  将head置空
		head = NULL;
	}
 
	free(p);
	p = NULL;
 
	return head;
}
 
 
//从中间删除
bool _d_list_del_mid_node(DL_LINK_LIST *p)
{
	if (p == NULL)
	{
		printf("@_d_list_del_mid_node, param in node is NULL, can not do insert\n");
		return false;
	}
 
	p->pre->next = p->next;	// 前节点指向后节点 next
	p->next->pre = p->pre;  // 后节点指向前节点 pre
 
 
	free(p);
	p = NULL;
 
	return true;
}
 
// 删除指定节点
DL_LINK_LIST * _d_list_del_by_data(DL_LINK_LIST *head, int data)
{
	if (head == NULL)
	{
		printf("@_d_list_del_by_data, param head is null, can not trans continue!\n");
		return head;
	}
 
	printf("@_d_list_del_by_data---->try to delete %d.\n", data);
 
	DL_LINK_LIST *p = head;
	while (p->next != NULL && (p->data != data))
	{
		p = p->next;
	}
 
	if (p->data == data)
	{
		// 如果是头结点
		if(p == head)
		{
			// 删除头
			head = _d_list_del_head(head);
		}
		else
		{
			if (p->next == NULL)
			{
				// 删除尾节点
				head = _d_list_del_tail(head);
			}
			else
			{
				// head 不变
				(void)_d_list_del_mid_node(p);
			}
		}
	}
	else
	{
		printf("@_d_list_del_by_data, can not find the data %d\n", data);
	}
 
	return head;
}
 
void _d_list_del_all(DL_LINK_LIST *head)
{
	printf("_d_list_del_all******************\n");
	while (head != NULL)
	{
		//head = _d_list_del_head(head);  //测试通过
		head = _d_list_del_tail(head);
	}
}
 
 
void _d_list_diaplay(DL_LINK_LIST* head)
{
	printf("__d_list_diaplay******************\n");
 
	DL_LINK_LIST *p = head;
	int i = 1;
	while (p != NULL)
	{
		printf("_d_list_ Num %d data = %d.\n", i, p->data);
		p = p->next;
		i++;
	}
}
 
int main()
{
    std::cout << "Hello World!\n";
	// 创建双向链表
	DL_LINK_LIST *head = (DL_LINK_LIST*)malloc(sizeof(DL_LINK_LIST));
	init_d_list_node(head, -1);
	for (int i = 0; i < (13*10); i+= 13)
	{
		// apped5个 
		if(i <13*5)
		{
			// 尾插入
			head = _d_list_add_tail(head, i);
		}
		else
		{
			//尾插入
			head = _d_list_add_head(head, i);
		}
	}
 
	_d_list_diaplay(head);
	// 插入中间数值
	head = _d_list_insert_by_data(head, 14);
	head = _d_list_insert_by_data(head, 33);
	head = _d_list_insert_by_data(head, 120);
	_d_list_diaplay(head);
	// 删除中间值
	head = _d_list_del_by_data(head, 15);
	head = _d_list_del_by_data(head, 26);
	_d_list_diaplay(head);
	// 删除头  
	head = _d_list_del_by_data(head, 14);
	// 删除尾
	head = _d_list_del_by_data(head, 120);
	_d_list_diaplay(head);
	_d_list_del_all(head);
 
}
 

老师的代码

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

/**
 * Double linked list of integers. The key is char.
 */
typedef struct DoubleLinkedNode{
	char data;
	struct DoubleLinkedNode *previous;
	struct DoubleLinkedNode *next;
} DLNode, *DLNodePtr;

/**
 * Initialize the list with a header.
 * @return The pointer to the header.
 */
DLNodePtr initLinkList(){
	DLNodePtr tempHeader = (DLNodePtr)malloc(sizeof(struct DoubleLinkedNode));
	tempHeader->data = '\0';
	tempHeader->previous = NULL;
	tempHeader->next = NULL;
	return tempHeader;
}// Of initLinkList

/**
 * Print the list.
 * @param paraHeader The header of the list.
 */
void printList(DLNodePtr paraHeader){
	DLNodePtr p = paraHeader->next;
	while (p != NULL) {
		printf("%c", p->data);
		p = p->next;
	}// Of while
	printf("\r\n");
}// Of printList

/**
 * Insert an element to the given position.
 * @param paraHeader The header of the list.
 * @param paraChar The given char.
 * @param paraPosition The given position.
 */
void insertElement(DLNodePtr paraHeader, char paraChar, int paraPosition){
	DLNodePtr p, q, r;

	// Step 1. Search to the position.
	p = paraHeader;
	for (int i = 0; i < paraPosition; i ++) {
		p = p->next;
		if (p == NULL) {
			printf("The position %d is beyond the scope of the list.", paraPosition);
			return;
		}// Of if
	} // Of for i

	// Step 2. Construct a new node.
	q = (DLNodePtr)malloc(sizeof(struct DoubleLinkedNode));
	q->data = paraChar;

	// Step 3. Now link.
	r = p->next;
	q->next = p->next;
	q->previous = p;
	p->next = q;
	if (r != NULL) {
		r->previous = q;
	}// Of if
}// Of insertElement

/**
 * Delete an element from the list.
 * @param paraHeader The header of the list.
 * @param paraChar The given char.
 */
void deleteElement(DLNodePtr paraHeader, char paraChar){
	DLNodePtr p, q, r;
	p = paraHeader;

	// Step 1. Locate.
	while ((p->next != NULL) && (p->next->data != paraChar)){
		p = p->next;
	}// Of while

	// Step 2. Error check.
	if (p->next == NULL) {
		printf("The char '%c' does not exist.\r\n", paraChar);
		return;
	}// Of if

	// Step 3. Change links.
	q = p->next;
	r = q->next;
	p->next = r;
	if (r != NULL) {
		r->previous = p;
	}// Of if

	// Step 4. Free the space.
	free(q);
}// Of deleteElement

/**
 * Unit test.
 */
void insertDeleteTest(){
	// Step 1. Initialize an empty list.
	DLNodePtr tempList = initLinkList();
	printList(tempList);

	// Step 2. Add some characters.
	insertElement(tempList, 'H', 0);
	insertElement(tempList, 'e', 1);
	insertElement(tempList, 'l', 2);
	insertElement(tempList, 'l', 3);
	insertElement(tempList, 'o', 4);
	insertElement(tempList, '!', 5);
	printList(tempList);

	// Step 3. Delete some characters (the first occurrence).
	deleteElement(tempList, 'e');
	deleteElement(tempList, 'a');
	deleteElement(tempList, 'o');
	printList(tempList);

	// Step 4. Insert to a given position.
	insertElement(tempList, 'o', 1);
	printList(tempList);
}// Of appendInsertDeleteTest

/**
 * Address test: beyond the book.
 */
void basicAddressTest(){
	DLNode tempNode1, tempNode2;

	tempNode1.data = 4;
	tempNode1.next = NULL;

	tempNode2.data = 6;
	tempNode2.next = NULL;

	printf("The first node: %d, %d, %d\r\n",
		&tempNode1, &tempNode1.data, &tempNode1.next);
	printf("The second node: %d, %d, %d\r\n",
		&tempNode2, &tempNode2.data, &tempNode2.next);

	tempNode1.next = &tempNode2;
}// Of basicAddressTest

/**
 * The entrance.
 */
void main(){
	insertDeleteTest();
	basicAddressTest();
}// Of main