数据结构——带头结点链表和不带头结点链表操作比较

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

typedef int elemType;
typedef struct Node{//定义链接节点
elemType element;
Node* next;
}Node;
int insertLast(Node** pNode, elemType ele);
//1、初始化链表，未带头结点
void init(Node** pNode){
*pNode = NULL;
printf("------>链表初始化<------\n");
}

void init_n(Node** pNode){
*pNode = (Node*)malloc(sizeof(Node));//产生头结点，并使pNode头指针指向头结点
if (!(*pNode)){
printf("头结点初始化空间失败\n");
}
printf("------>链表初始化<------\n");
(*pNode)->next = NULL;
}
//1、创建链表
Node* create(Node* pHead){
Node* p1;//代表新节点
Node * p2;//代表尾节点
p1 = p2 = (Node*)malloc(sizeof(Node));//申请节点
if (p1 == NULL || p2 == NULL){
printf("内存空间申请失败\n");
exit(0);
}
memset(p1, 0, sizeof(Node));
printf("输入节点值(非正数结束)：");
scanf_s("%d", &p1->element);//输入新节点
p1->next = NULL;
while (p1->element > 0){
if (pHead == NULL){//空节点,接入表头
pHead = p1;
}
else{
p2->next = p1;//非空表，接入尾节点
}
p2 = p1;//重新让p2做尾节点
p1 = (Node*)malloc(sizeof(Node));
if (p1 == NULL || p2 == NULL){
printf("内存分配失败\n");
exit(0);
}
memset(p1, 0, sizeof(Node));
printf("输入节点值(非正数结束)：");
scanf_s("%d", &p1->element);
p1->next = NULL;

}

printf("链表创建成功\n");
return pHead;
}

Node* create_n(Node* pHead){
Node* p1;//代表新节点
Node * p2;//代表尾节点
p1 = p2 = (Node*)malloc(sizeof(Node));//申请节点
if (p1 == NULL || p2 == NULL){
printf("内存空间申请失败\n");
exit(0);
}
memset(p1, 0, sizeof(Node));
printf("输入节点值(非正数结束)：");
scanf_s("%d", &p1->element);//输入新节点
p1->next = NULL;
while (p1->element > 0){

insertLast(&pHead, p1->element);
memset(p1, 0, sizeof(Node));
printf("输入节点值(非正数结束)：");
scanf_s("%d", &p1->element);
p1->next = NULL;

}

printf("链表创建成功\n");
return pHead;
}

//打印链表,不带头结点的情况
void print(Node* pHead){
if (pHead == NULL){
printf("链表为空\n");
}
else{
while (pHead != NULL){

printf("%d,", pHead->element);
pHead = pHead->next;

}
printf("\n");
}
}

//打印链表，带头结点的情况
void print_n(Node* pHead){
pHead = pHead->next;//第一元素结点
if (pHead == NULL){
printf("链表为空\n");
}
else{
while (pHead != NULL){

printf("%d,", pHead->element);
pHead = pHead->next;

}
printf("\n");
}
}

//插入尾节点
int insertLast(Node** pNode, elemType ele){
Node* pInsert;
Node* pHead;
Node* pTmp;

pHead = *pNode;
pTmp = pHead;
pInsert = (Node* )malloc(sizeof(Node));
memset(pInsert, 0, sizeof(Node));
pInsert->element = ele;
while (pHead->next != NULL){
pHead = pHead->next;
}
pHead->next = pInsert;
*pNode = pTmp;
printf("向表尾插入元素:%d\n",ele);
return 1;
}

void main(){
Node* pList=NULL;
Node* list;

init(&pList);
pList = create(pList);
print(pList);

init_n(&list);
pList = create_n(list);
print_n(list);

system("pause");
}