大家帮我看看这个链表有什么缺陷？PS:删除还没写，继续更新中

#include "stdafx.h"
#include <stdio.h>
#include <iostream>
using namespace std;
#define ZERO 0

class Node
{
public:
    int num;                    //value
    Node* next;                 //下一个节点
    Node* head;                 //头结点
    void creat();               //创建链表
    void show();                //显示链表
    void insert_front();       //头插入节点
    void insert_real();        //尾插入节点
    void insert_center();      //中间插入节点
    void delete_node();        //删除节点
};

void Node::creat()
{
    int count=0;
    cout<<"please input Node Num";
    cin>>count;
    if (count <= ZERO)
    {
        head = NULL;
        return ;
    }
    Node* p1 = new Node;
    Node* p2;
    head = p1;
    for (int i = 0 ; i < count ;++i)
    {
        cout<<i+1<<":";
        cin>>p1->num;
        p2 = p1;
        p1= new Node;
        p2->next = p1;
    }
    delete p1;
    p2->next = NULL;
    return ;

}

void Node::show()
{
    Node* tmp = head;
    while(tmp)
    {
        cout<<tmp->num<<endl;
        tmp = tmp->next;
    }
    delete tmp;
}

void Node::insert_front()
{
    Node* tmp_Node = new Node;
    cout<<"input insert of front num:"<<endl;
    cin>>tmp_Node->num;
    tmp_Node->next = head;
    head = tmp_Node;
}

void Node::insert_center()
{
    //插入的数据
    Node* tmp_Node = new Node;
    //插入的位置
    int postion;
    cout<<"input insert of center num:"<<endl;
    //输入插入数据
    cin>>tmp_Node->num;
    cout<<"insert postion"<<endl;
    //输入插入位置
    cin>>postion;
    //判断异常
    if (postion <= ZERO)
    {
        return ;
    }
    //创建head头结点副本
    Node* tmp = head;
    //循环跳转节点
    for (int i = 0 ; i < postion-1 ; ++i)
    {
        tmp = tmp->next;
    }
    //插入数据，前一个节点
    Node* tmpePos = tmp;
    Node* tmpeNext = tmp->next;
    //将该节点的next指向新节点
    tmpePos->next = tmp_Node;

    //新节点的next指向原始节点的next
    tmp_Node->next = tmpeNext;
}


void Node::insert_real()
{
    Node* tmp_Node = new Node;
    cout<<"input insert of real num:"<<endl;
    cin>>tmp_Node->num;
    Node*tmp = head;
    while(tmp)
    {
        if (tmp->next == NULL)
        {
            tmp->next = tmp_Node;
            tmp_Node->next = NULL;
            //break;
        }
        tmp = tmp->next;
    }
    delete tmp;
}



void Node::delete_node()
{
    Node* tmpHead = head;
    Node* temp;
    int del_num;
    cout<<"input delete num : ";
    cin>>del_num;
    if (tmpHead->num == del_num)
    {
        temp = tmpHead;
        head = tmpHead->next;
        delete temp;
        cout<<"delete front num "<<endl;
        return ;
    }
    while(tmpHead)
    {
        if (tmpHead->next->num == del_num)
        {
            temp = tmpHead->next;
            tmpHead->next = temp->next;
            delete temp;
            cout<<"delete center num "<<endl;
            return;
        }
        tmpHead = tmpHead->next;
    }
    cout<<"Delete fail "<<endl;
}