头插法和尾插法

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
typedef struct LinkNode
{
	int num;
	LinkNode* next;
}Lk, * lk;
//初始化头节点
lk init_headNode()
{
	//生成一个头节点
	lk headNode = (lk)malloc(sizeof(Lk));
	//检查分配空间是否成功
	if (headNode == NULL)
	{
		return NULL;
	}
	//数据域可以不用维护
	headNode->next = NULL;
	return headNode;
}
//头插法
void insert_LinkList(lk headNode,int length)
{
	//检查传入的头节点是否为空
	if (headNode == NULL)
	{
		return ;
	}
	int val = 0;
	int index = 0;
	for (int i = 0; i < length; i++)
	{
		lk  newNode = (lk)malloc(sizeof(Lk));
		printf("请输入第%d个值：\n", (index++)+ 1);
		scanf("%d", &val);
		newNode->num = val;
		newNode->next = NULL;
		//下面两行代码不能反
		newNode->next = headNode->next;
		headNode->next = newNode;
	}

}
//遍历链表
void outputLinkList(lk headNode)
{
	if (headNode == NULL)
		return;
	//创建一个指针指向当前节点
	lk curNode = headNode->next;
	while (curNode)
	{
		printf("%d\n", curNode->num);
		curNode = curNode->next;
	}
}
int main()
{
	lk headNode = init_headNode();
	int length = 0;
	printf("请输入所要输入的元素个数:\n");
	scanf("%d", &length);
	insert_LinkList(headNode,length);
	printf("打印链表：\n");
	outputLinkList(headNode);
	return 0;
}

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
typedef struct LinkNode
{
	int num;
	LinkNode* next;
}Lk, * lk;
//初始化头节点
lk init_headNode()
{
	//生成一个头节点
	lk headNode = (lk)malloc(sizeof(Lk));
	//检查分配空间是否成功
	if (headNode == NULL)
	{
		return NULL;
	}
	//数据域可以不用维护
	headNode->next = NULL;
	return headNode;
}
//尾插法
void insert_LinkList(lk headNode,int length)
{
	//检查传入的头节点是否为空
	if (headNode == NULL)
	{
		return ;
	}
	int val = 0;
	int index = 0;
	//创建一个尾指针，指向链表尾部，一开始头部即尾部
	lk endNode = headNode;
	for (int i = 0; i < length; i++)
	{
		printf("请输入第%d个数据:\n", (index++) + 1);
		scanf("%d", &val);
		lk newNode = (lk)malloc(sizeof(Lk));
		newNode->num = val;
		newNode->next = NULL;

		//下面两行顺序不能反
		endNode->next = newNode;
		endNode = newNode;
	}
	//因为我们上面已经写了newNode->next=NULL
	//因此下面这句话就可以不写
	//当尾指针指向最后一个节点的时候，要将他的next指针置空，防止出现野指针
	endNode->next = NULL;
}
//遍历链表
void outputLinkList(lk headNode)
{
	if (headNode == NULL)
		return;
	//创建一个指针指向当前节点
	lk curNode = headNode->next;
	while (curNode)
	{
		printf("%d\n", curNode->num);
		curNode = curNode->next;
	}
}
int main()
{
	lk headNode = init_headNode();
	int length = 0;
	printf("请输入所要输入的元素个数:\n");
	scanf("%d", &length);
	insert_LinkList(headNode,length);
	printf("打印链表：\n");
	outputLinkList(headNode);
	return 0;
}