链表的一点总结

//总结：1.参数检查 对于插入操作等要检查插入位置等 对于删除操作要检查链表是否为空
//      2.创建链表可以不将创建所有的节点放在整个函数中，而是写一个类似的CreateNode(struct node* p_head, elemtype e)之类的函数

//链表的基本操作的实现，使用单个的函数实现逐个的操作

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

///////////////////////////////////

//创建链表 参数为头指针和新建节点的个数
int CreateLinkList(struct node* p_head, int n);
//插入节点，参数为头指针，和插入位置。其中位置使用一个整数location来表达。
//对location参数要进行判断。
//1.loaction < 0抛出异常  2.location = 0这样插入的节点就成了第一个节点，注意转移头指针 3.loaction超过链表的节点个数，异常
int InsertNode(struct node* p_head, int location, int id);

//获取链表的长度，就是节点的个数,参数为头指针
int GetLength(struct node* p_head);
//打印整个链表 参数为头指针
void ShowLinkList(struct node* p_head);

///////////////////////////////////

//定义结构体  数据结构核心
struct node
{
int id;
//char name[20];
struct node* next;
};

//p_head头指针，永远指向第一个节点
struct node* p_head = NULL;
//p_node可以指向任意一个节点
struct node* p_node;
//new_node指针
struct node* new_node;

//主函数////////////////////////////
int main(int argc, char* argv[])
{

//创建一个链表  参数是头指针？
//printf("%d\n",CreateLinkList(p_head, 5));
CreateLinkList(p_head, 5);
ShowLinkList(p_head);
printf("length = %d", GetLength(p_head));

///////////////////////////////////////
//主函数结束 不要修改
getchar();
return 0;
}

int CreateLinkList(struct node* p_head, int n)
{
int i;
//新建第一个节点
new_node = (struct node*)malloc(sizeof(struct node));
new_node -> next = NULL;
new_node -> id = 0;
//strcpy(new_node -> name, "a");
//p_head和p_node都是指向第一个节点
p_head = new_node;
p_node = new_node;
for(i = 0;i < n - 1;i++)
{
new_node = (struct node*)malloc(sizeof(struct node));
new_node -> next = NULL;
new_node -> id = i + 1;
//p_node后移 指针变换
p_node -> next = new_node;
//p_node = p_node -> next;
p_node = new_node;
}
//成功标志？
//printf("1");
return 1;
}

int GetLength(struct node* p_head)
{
int length = 0;
for(p_node = p_head;p_node != NULL;p_node = p_node -> next)
{
length++;
}
return length;
}

void ShowLinkList(struct node* p_head)
{
for(p_node = p_head;p_node != NULL;p_node = p_node -> next)
{
printf("%d\n", p_node -> id);
}
}

int InsertNode(struct node* p_head, int location, int id)
{
int n = 1;
if(location < 0 || location > GetLength(p_head))
{
printf("错误，插入位置错误");
//错误处理 暂时省略
}
if(location = 0)
{
new_node = (struct node*)malloc(sizeof(struct node));
new_node -> id = id;
new_node -> next = p_head;
p_head = new_node;
}
else
{
for(p_node = p_head;n < location;p_node = p_node -> next)
{
n++;
}
new_node = (struct node*)malloc(sizeof(struct node));
new_node -> id = id;
new_node -> next = p_node -> next;
p_node -> next = new_node;
}
return 1;
}

#include <stdio.h>
#include <stdlib.h>
struct Node{
int data;
struct Node *next;
};
void InitList(struct Node **pHead);
struct Node* CreatNode(int d);
struct Node* FindKth(struct Node* head, int k);
int Insert(struct Node** pHead, int index, int element);
void PrintList(struct Node* head);
void DestroyList(struct Node** pHead);
int DeleteNode(struct Node** pHead, int index);
int main(){

struct Node *head;
InitList(&head);
Insert(&head, 1, 6);
Insert(&head, 1, 61);
Insert(&head, 1, 62);
Insert(&head, 1, 63);
Insert(&head, 1, 64);
PrintList(head);
printf("%d\n",DeleteNode(&head, 6));
PrintList(head);
DestroyList(&head);
return 0;
}
int DeleteNode(struct Node** pHead, int index){
struct Node* pTmp, *pNodeToBeDeleted;
if (*pHead == NULL) {
return -1;
}
if (index == 1) {
pTmp = *pHead;
*pHead = (*pHead)->next;
free(pTmp);
return 0;
}
pTmp = FindKth(*pHead, index-1);
if (!pTmp) { // if(pTmp == NULL)
return -2;
}
if (pTmp->next == NULL) {
return -3;
}
pNodeToBeDeleted = pTmp->next;
pTmp->next = pNodeToBeDeleted->next;
free(pNodeToBeDeleted);
return 0;
}
void DestroyList(struct Node** pHead){
struct Node* pTmp;

while (*pHead) {
pTmp = *pHead;
*pHead = (*pHead)->next;
free(pTmp);
}
}
void PrintList(struct Node* head){
struct Node* pTmp;
pTmp = head;
while (pTmp) {
printf("%d  ",pTmp->data);
pTmp = pTmp->next;
}
printf("\n");
}
int Insert(struct Node** pHead, int index, int element){
struct Node* pTmp, *pTmpNode;
if (index == 1) {
pTmpNode = CreatNode(element);
pTmpNode->next = *pHead;
*pHead = pTmpNode;
return 0;
}
else{
pTmp = FindKth(*pHead, index-1);
if (pTmp) {
pTmpNode = CreatNode(element);
pTmpNode->next = pTmp->next;
pTmp->next = pTmpNode;
return 0;
}
else return -1;
}
}
struct Node* FindKth(struct Node* head, int k){
struct Node* pTmp;
pTmp = head;
int i=1;
while (pTmp && i<k) {
pTmp = pTmp->next;
i++;
}
return pTmp;
}
void InitList(struct Node **pHead){
*pHead = NULL;
}
struct Node* CreatNode(int d){
struct Node* pTmp;
pTmp = (struct Node*)malloc(sizeof(struct Node));
pTmp->data = d;
pTmp->next = NULL;

return pTmp;
}