创建 C++ 单链表实现

Question

我是面向对象编程的新手，我正在尝试完成这个涉及从链表中插入和删除数据的硬件任务。我想我已经创建了节点，但我不知道为什么我不能显示它。我想确保在继续之前确实添加了节点。任何帮助将不胜感激！

#include <iostream>
using namespace std;

//void addNode(int num);
//void displayList();

struct node{
  //Where the data within the node is intialized
  int data;

  //Where the node advancement pointer is intialized
  node *next;
};

class list{
 private:
  //Where the head and tail pointers are intialized, these will hold the first and last node (in order to not lose track)
  node *head,*tail;

  public:
  //The constructor (for the class)
  list()
  {
    //Where the node header is set to NULL
    head=NULL;
    //Where the node tail is set to NULL
    tail=NULL;
  }

  void addNode(int num)
  {
    //A temp node is made by calling the node struct
    node *temp=new node;

    //The user entered number is added to the data portion of the node in the list
    temp->data=num;
    //The new tail is made and pointed to
    temp->next=NULL;


    if(head == NULL)
      {
        //If the data being entered is the first node
        //First andlast nodes is the data being entered
        head = temp;
        tail = temp;
      }
    else
    {
      //Set node after tail (last node) equal to the data being entered
      tail->next = temp;
      //Set the tail (last node) equal to the node after temp
      tail = tail->next;
    }
  }

  void displayList()
  {
    node *displayNode=new node;
    displayNode=head;

    if(displayNode!=NULL)
    {
      cout<<"display list";
      cout<<displayNode->data<<endl;
      displayNode=displayNode->next;
    }
  }

};

int main() {
  //Creating arguments for the list class
  list first;
  list second;
  list third;

  //Where the class member functions are called with the data 1, 2, and 3
  first.addNode(1);
  second.addNode(2);
  third.addNode(3);

  //Whre the display calss member function is called
  list print;
  print.displayList();
}

Answer 1

为了打印列表，您需要在 displayList() 函数中使用具有相同条件的 while。 在列表上运行直到 node->next 的 while 循环将指向 NULL 值（这意味着这是列表的末尾）。

在main()中你只需要初始化一个列表并将所有的值添加进去。

另外，一个代码风格推荐是用大写字母开头，每个新词都有一个大写字母，这样区分函数和类很有用，例如：

class MyClass
{

};

struct MyStruct
{

};

代码如下：

#include <iostream>
using namespace std;

//void addNode(int num);
//void displayList();

struct Node{
  //Where the data within the node is intialized
  int data;

  //Where the node advancement pointer is intialized
  Node *next;
};

class List{
 private:
  //Where the head and tail pointers are intialized, these will hold the first and last node (in order to not lose track)
  Node *head,*tail;

  public:
  //The constructor (for the class)
  List()
  {
    //Where the node header is set to NULL
    head=NULL;
    //Where the node tail is set to NULL
    tail=NULL;
  }

  void addNode(int num)
  {
    //A temp node is made by calling the node struct
    Node *temp=new Node;

    //The user entered number is added to the data portion of the node in the list
    temp->data=num;
    //The new tail is made and pointed to
    temp->next=NULL;


    if(head == NULL)
      {
        //If the data being entered is the first node
        //First andlast nodes is the data being entered
        head = temp;
        tail = temp;
      }
    else
    {
      //Set node after tail (last node) equal to the data being entered
      tail->next = temp;
      //Set the tail (last node) equal to the node after temp
      tail = tail->next;
    }
  }

  void displayList()
  {
    Node *displayNode=new Node;
    displayNode=head;

    while(displayNode!=NULL)
    {
      cout<<"display list";
      cout<<displayNode->data<<endl;
      displayNode=displayNode->next;
    }
  }

};

int main() {
  //Creating arguments for the list class
  List first;

  //Where the class member functions are called with the data 1, 2, and 3
  first.addNode(1);
  first.addNode(2);
  first.addNode(3);

  //Whre the display calss member function is called
  first.displayList();
}