码海拾遗：简单的链表类

　　简单的链表练习。。。。。。

　　实现：myList.h

#pragma once

#include <iostream>

using namespace std;

typedef struct _Node
{
    _Node* next;
    int data;
}Node;

class myList
{
public:
    //初始化
    myList();
    //销毁链表
    void Destroy();
    //获取链表长度
    int getLength();
    //获取指定位置的元素
    Node* getElement(int pos);
    //插入元素
    bool insertElement(Node* node, int pos);
    bool insertElement(Node* node);
    //删除指定位置元素
    bool delElement(int pos);
    //打印链表
    void show();

    ~myList();
private:
    Node *head;
    int length;
};

　　myList.cpp

#include "myList.h"



myList::myList()
{
    head = new Node;
    if (NULL != head)
    {
        head->next = NULL;
        head->data = 0;
        length = 0;
    }
    else
    {
        cout << "初始化失败" << endl;
    }
}

void myList::Destroy()
{
    if (NULL != head)
    {
        delete head;
        head = NULL;
        length = 0;
    }
}

int myList::getLength()
{
    return length;
}

Node * myList::getElement(int pos)
{
    if (pos > length)
    {
        cout << "访问越界" << endl;
        return NULL;
    }

    if (head->next != NULL)
    {
        Node* curNode = head->next;
        for (int i = 0; i < pos; ++i)
            curNode = curNode->next;
        return curNode;
    }
    else
    {
        cout << "链表为空" << endl;
        return NULL;
    }
}

bool myList::insertElement(Node * node, int pos)
{
    if (pos > length)
    {
        cout << "访问越界" << endl;
        return false;
    }
    else if (pos == length)
    {
        Node *curNode = head->next;
        while (curNode->next)
            curNode = curNode->next;
        curNode->next = node;
        length += 1;
        return true;
    }
    else
    {
        Node *curNode = head->next;
        for (int i = 0; i < pos-1; ++i)
            curNode = curNode->next;

        node->next = curNode->next;
        curNode->next = node;
        length += 1;
        return true;
    }
}


bool myList::insertElement(Node * node)
{
    if (length == 0)
        head->next = node;
    else
    {
        Node *curNode = head->next;
        while (curNode->next)
            curNode = curNode->next;
        curNode->next = node;
    }    
    length += 1;
    return true;
}

bool myList::delElement(int pos)
{
    if (pos > length)
    {
        cout << "访问越界" << endl;
        return false;
    }
    else if (pos == length)
    {
        Node *curNode = head->next;
        for (int i = 0; i < pos-1; ++i)
            curNode = curNode->next;
        delete curNode;
        length--;
        return true;
    }
    else
    {
        Node *curNode = head->next;
        for (int i = 0; i < pos-1; ++i)
            curNode = curNode->next;
        Node* tmp = curNode->next;
        curNode->next = curNode->next->next;
        delete tmp;
        length--;
        return true;
    }
}

void myList::show()
{
    if (length > 0)
    {
        Node *curNode = head->next;
        while (curNode)
        {
            cout << curNode->data << endl;
            curNode = curNode->next;
        }
    }
    else
        cout << "空" << endl;
}

myList::~myList()
{
    Destroy();
}