数据结构示例-创建并显示循环链表

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📜 数据结构示例-创建并显示循环链表

📅 最后修改于: 2020-10-15 06:01:35 🧑 作者: Mango

问：程序创建和显示循环链接列表。

说明

在此程序中，我们将创建一个循环链接列表，并print列表中存在的所有节点。

循环链表：

循环链表是一种链表。首先，节点是列表的元素，它具有两个部分，分别是数据和下一部分。数据表示存储在节点中的数据，下一个是指向下一个节点的指针。头将指向列表的第一个元素，而尾将指向列表的最后一个元素。在简单链表中，所有节点都将指向其下一个元素，而尾部将指向null。

循环链表是节点的集合，其中尾节点也指向头节点。下图显示了一个循环链表。节点A代表头，节点D代表尾。因此，在此列表中，A指向B，B指向C，C指向D，但使之成为圆形的是节点D指向节点A。

算法

定义一个Node类，该类代表列表中的一个节点。它具有两个属性数据，下一个将指向下一个节点。
定义另一个用于创建循环链接列表的类，它具有两个节点：head和tail。它有两种方法：add()和display()。
add()会将节点添加到列表中：
1. 它首先检查head是否为空，然后将节点插入为head。
2. 头部和尾部都将指向新添加的节点。
3. 如果head不为空，则新节点将是新尾，并且新尾将指向头，因为它是一个循环链接列表。
display()将显示列表中存在的所有节点。
1. 定义一个新节点“当前”，该节点将指向头部。
2. 打印current.data直到电流指向head
3. 当前将在每次迭代中指向列表中的下一个节点。

示例：

Python

#Represents the node of list.
class Node:
  def __init__(self,data):
    self.data = data;
    self.next = None;
 
class CreateList:
  #Declaring head and tail pointer as null.
  def __init__(self):
    self.head = Node(None);
    self.tail = Node(None);
    self.head.next = self.tail;
    self.tail.next = self.head;
    
  #This function will add the new node at the end of the list.
  def add(self,data):
    newNode = Node(data);
    #Checks if the list is empty.
    if self.head.data is None:
      #If list is empty, both head and tail would point to new node.
      self.head = newNode;
      self.tail = newNode;
      newNode.next = self.head;
    else:
      #tail will point to new node.
      self.tail.next = newNode;
      #New node will become new tail.
      self.tail = newNode;
      #Since, it is circular linked list tail will point to head.
      self.tail.next = self.head;
 
  #Displays all the nodes in the list
  def display(self):
    current = self.head;
    if self.head is None:
      print("List is empty");
      return;
    else:
        print("Nodes of the circular linked list: ");
        #Prints each node by incrementing pointer.
        print(current.data),
        while(current.next != self.head):
            current = current.next;
            print(current.data),
 
 
class CircularLinkedList:
  cl = CreateList();
  #Adds data to the list
  cl.add(1);
  cl.add(2);
  cl.add(3);
  cl.add(4);
  #Displays all the nodes present in the list
  cl.display();

输出：

Nodes of the circular linked list: 
1 2 3 4

C

#include 
#include 
#include 
 
//Represents the node of list.
struct node{
    int data;
    struct node *next;
};
 
//Declaring head and tail pointer as null.
struct node *head = NULL;
struct node *tail = NULL;
 
//This function will add the new node at the end of the list.
void add(int data){
    //Create new node
    struct node *newNode = (struct node*)malloc(sizeof(struct node));
    newNode->data = data;
    //Checks if the list is empty.
    if(head == NULL){
        //If list is empty, both head and tail would point to new node.
        head = newNode;
        tail = newNode;
        newNode->next = head;
    }else {
        //tail will point to new node.
        tail->next = newNode;
        //New node will become new tail.
        tail = newNode;
        //Since, it is circular linked list tail will point to head.
        tail->next = head;
    }
}
 
//This function will display the nodes of circular linked list
void display(){
    struct node *current = head;
    if(head == NULL){
        printf("List is empty");
    }
    else{
        printf("Nodes of the circular linked list: \n");
         do{
             //Prints each node by incrementing pointer.
            printf("%d ", current->data);
            current = current->next;
        }while(current != head);
        printf("\n");
    }
}
    
int main()
{
    //Adds data to the list
   add(1);
   add(2);
   add(3);
   add(4);
   //Displays all the nodes present in the list
   display();
   
   return 0;
}

输出：

Nodes of the circular linked list: 
1 2 3 4

JAVA

public class CreateList {
    //Represents the node of list.
    public class Node{
        int data;
        Node next;
        public Node(int data) {
            this.data = data;
        }
    }
    
    //Declaring head and tail pointer as null.
    public Node head = null;
    public Node tail = null;
    
    //This function will add the new node at the end of the list.
    public void add(int data){
        //Create new node
        Node newNode = new Node(data);
        //Checks if the list is empty.
        if(head == null) {
             //If list is empty, both head and tail would point to new node.
            head = newNode;
            tail = newNode;
            newNode.next = head;
        }
        else {
            //tail will point to new node.
            tail.next = newNode;
            //New node will become new tail.
            tail = newNode;
            //Since, it is circular linked list tail will point to head.
            tail.next = head;
        }
    }
    
    //Displays all the nodes in the list
    public void display() {
        Node current = head;
        if(head == null) {
            System.out.println("List is empty");
        }
        else {
            System.out.println("Nodes of the circular linked list: ");
             do{
                //Prints each node by incrementing pointer.
                System.out.print(" "+ current.data);
                current = current.next;
            }while(current != head);
            System.out.println();
        }
    }
    
    public static void main(String[] args) {
        CreateList cl = new CreateList();
        //Adds data to the list
        cl.add(1);
        cl.add(2);
        cl.add(3);
        cl.add(4);
        //Displays all the nodes present in the list
        cl.display();
    }
}

输出：

Nodes of the circular linked list: 
1 2 3 4

C＃

 using System; 
namespace CircularLinkedList 
{                     
    public class Program
    {
        //Represents the node of list.
        public class Node{
            public T data;
            public Node next;
            public Node(T value) {
                data = value;
                next = null;
            }
        }
        
        public class CreateList{
            protected Node head = null;             
             protected Node tail = null;
            
            //This function will add the new node at the end of the list.
            public void add(T data){
                //Create new node
                Node newNode = new Node(data);
                //Checks if the list is empty.
                if(head == null){
                    head = newNode;
                    tail = newNode;
     newNode.next = head;
                }else{
                    //tail will point to new node.
                    tail.next = newNode;
                    //New node will become new tail.
                    tail = newNode;
                    //Since, it is circular linked list tail will point to head.
                    tail.next = head;
                }
            }
            
            //Displays all the nodes in the list
            public void display(){
                Node current;
                if(head == null){
                    Console.WriteLine("List is empty");
                }
                else{
                    //Prints each node by incrementing pointer.
                    Console.WriteLine("Nodes of the circular linked list: ");
                    Console.Write(" "+head.data);
                    for(current = head.next; current!= head; current= current.next){
                        Console.Write(" "+current.data);
                    }
                }    
            }
        }
        
        public static void Main()
        {
            
        CreateList cl = new CreateList();
        //Adds data to the list
        cl.add(1);
        cl.add(2);
        cl.add(3);
        cl.add(4);
        //Displays all the nodes present in the list
        cl.display();
        }    
    }
}

输出：

Nodes of the circular linked list: 
1 2 3 4

PHP：




data = $data;
        $this->next = NULL;
    }
}
class CreateList{
    //Declaring head and tail pointer as null.
    private $head;
    private $tail;
    function __construct(){
        $this->head = NULL;
        $this->tail = NULL;
    }
    //This function will add the new node at the end of the list.
    function add($data){
        //Create new node
        $newNode = new Node($data);
        //Checks if the list is empty.
        if($this->head == NULL){
            //If list is empty, both head and tail would point to new node.
            $this->head = $newNode;
            $this->tail = $newNode;
            $newNode->next = $this->head;
        }
        else{
            //tail will point to new node.
            $this->tail->next = $newNode;
            //New node will become new tail.
            $this->tail = $newNode;
            //Since, it is circular linked list tail will point to head.
            $this->tail->next = $this->head;
        }
    }
    //Displays all the nodes in the list
    function display() {
        $current = $this->head;
        if($this->head == NULL) {
            echo "List is empty";
        }
        else {
            echo "Nodes of the circular linked list: 
";
             do{
                //Prints each node by incrementing pointer.
                echo(" $current->data");
                $current = $current->next;
            }while($current != $this->head);
            echo "
";
        }
    }   
}
$cl = new CreateList();
//Adds data to the list
$cl->add(1);
$cl->add(2);
$cl->add(3);
$cl->add(4);
//Displays all the nodes present in the list
$cl->display();
?>

输出：

Nodes of the circular linked list: 
1 2 3 4