C语言实现双链表（带头结点）_请基于输入数据创建一个带头结点的双向链表,并根据位置信息找到对应节点,返回节点

双链表是在单链表的基础上实现的，不过他们之间又有不同的之处。

1.在使用表头法插入的时候，需要注意的点是要判断表头的下一的元素是否为空（NULL）代码如下：

//4.链表的插入，表头插入法
void insertNewNodebyhead(struct Node* head, int data)
{
	struct Node* NewNode = createNewNode(data);//创建节点
	NewNode->next = head->next;
 
	if(head->next!=NULL)//如果表头的下一个节点不空的话
	  head->next->front = NewNode;
 
	NewNode->front = head;
	head->next = NewNode; 
}

2.在指定位置加入元素时，需要判度该位置是否存在，注意逻辑关系

完整代码:

#include<stdio.h>
#include<stdlib.h>
 
struct Node
{
	struct Node* front;
	int data;
	struct Node* next;
};
//1.创建表头，表示整个链表
struct Node* createlistHead()
{
	struct Node* listHead = (struct Node*)malloc(sizeof(struct Node));
	//初始化表头
	//表头无前驱
	//表头的无数据
	listHead->next = NULL;
	return listHead;   //函数为结构体指针函数，即返回结构体变量
 
}
//2.创建节点为插入做准备
struct Node* createNewNode(int data)
{
	struct Node* NewNode = (struct Node*)malloc(sizeof(struct Node));
	NewNode->data = data;
	NewNode->next = NULL;
	return NewNode;
}
//3.打印链表
void print(struct Node* Head)
{
	//创建一个移动指针指向该链表的头结点
	struct Node* Pmove;
	Pmove = Head->next;//表头为空从下一个节点开始打印
 
	while (Pmove != NULL)
	{
		printf("%d\t", Pmove->data);
		Pmove = Pmove->next;
	}
	printf("\n");
}
//4.链表的插入，表头插入法
void insertNewNodebyhead(struct Node* head, int data)
{
	struct Node* NewNode = createNewNode(data);//创建节点
	NewNode->next = head->next;
 
	if(head->next!=NULL)//如果表头的下一个节点不空的话
	  head->next->front = NewNode;
 
	NewNode->front = head;
	head->next = NewNode; 
}
//5.表尾插入法
void insertNewNodebytial(struct Node* head, int data)
{
	struct Node* NewNode = createNewNode(data);
 
	//创建一个指针去找到表尾
	struct Node* Ptail=head;
	while (Ptail->next != NULL)
	{
		Ptail = Ptail->next;
	}
 
	//退出循环即找到表尾
	NewNode->next = Ptail->next;
	NewNode->front = Ptail;
	Ptail->next = NewNode;
}
//6.在指定位置前插入
void insertNewNodebyAppoint(struct Node* head, int data,int m)
{
	struct Node* NewNode = createNewNode(data);
	//创建一个移动指针去找到该位置
	struct Node* Pmove = head;
 
	if (head->next == NULL)
	{
		printf("该链表为空！！！\n");
	}
	else
	{
		while (Pmove->data!=m)
		{
			Pmove = Pmove->next;
			if (Pmove == NULL)
			{
				printf("未能找到该信息！！\n");
				return;
			}
		}
		
		NewNode->next = Pmove;
		NewNode->front = Pmove->front;
		Pmove->front->next = NewNode;
		Pmove->front = NewNode;
	}
}
//7.表头删除
void deleteByhead(struct Node* head)
{
	if (head->next == NULL)
		printf("该链表为空!!!");
	else
	{
		struct Node* Delete = head->next;
 
		head->next = Delete->next;
		Delete->next->front = head;
		free(Delete);
		Delete = NULL;
	}
}
//8.表尾删除
void deleteBytial(struct Node* head)
{
	struct Node* Deletetial = head->next;
 
	if (Deletetial == NULL)
		printf("该链表为空！！！");
	else
	{
		while (Deletetial->next != NULL)
		{
			Deletetial = Deletetial->next;
		}
 
		Deletetial->front->next = Deletetial->next;
		free(Deletetial);
		Deletetial = NULL;
	}
}
//9.删除指定位置的元素
void deleteByAppoint(struct Node* head,int m)
{
	//创建一个移动的指针去找到指定位置
	struct Node* DeletePmove = head->next;
 
	if (DeletePmove == NULL)
		printf("该链表为空！！！！");
	else
	{
		while (DeletePmove->data != m)
		{
			DeletePmove = DeletePmove->next;
			if (DeletePmove == NULL)
			{
				printf("未能找到该位置！！\n");
				return;
			}
		}
 
		DeletePmove->next->front = DeletePmove->front;
		DeletePmove->front->next = DeletePmove->next;
		free(DeletePmove);
		DeletePmove = NULL;
	}
}
int main()
{
	int n;
	printf("请你输入你要插入数的个数：");
	scanf("%d", &n);
	printf("表头法插入list1链表：\n");
	struct Node* list1 = createlistHead();
 
	for (int i = 0; i < n; i++)
	{
		int m;
		scanf("%d", &m);
		insertNewNodebyhead(list1, m);//调用表头法插入函数
	}
 
	print(list1);
 
	printf("请输入你要插入的元素个数：");
	scanf("%d", &n);
	printf("表尾法插入list2链表：\n");
	struct Node* list2 = createlistHead();
 
	for (int i = 0; i < n; i++)
	{
		int m;
		scanf("%d", &m);
		insertNewNodebytial(list2, m);
	}
 
	print(list2);
 
	printf("在指定list2链表中插入元素\n");
	int k,l;
	printf("请你输入在那个元素之前插入和插入的值：");
	scanf("%d %d", &k,&l);
	insertNewNodebyAppoint(list2, l, k);
 
	print(list2);
 
	printf("表头删除list2的元素\n");
	deleteByhead(list2);
 
	print(list2);
 
	printf("表尾删除list2的元素\n");
	deleteBytial(list2);
 
	print(list2);
 
	printf("请你输入删除list2中的元素值：");
	int m;
	scanf("%d", &m);
	deleteByAppoint(list2, m);
 
	print(list2);
	system("pause");
	return 0;
}