数据结构示例-循环链表的末端插入新节点

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📜 数据结构示例-循环链表的末端插入新节点

📅 最后修改于: 2020-10-15 06:03:48 🧑 作者: Mango

问：程序在循环链表的末尾插入一个新节点。

说明

在此程序中，我们将创建一个循环链接列表，并将每个新节点插入列表的末尾。如果列表为空，则头和尾将指向新添加的节点。如果列表不为空，则新添加的节点将成为列表的新尾部。前一条尾巴将指向新节点作为其下一个节点。由于它是一个循环链表；新的尾巴将指向头部。换句话说，新节点将成为列表的最后一个节点(尾)，而前一条尾将成为倒数第二个节点。

将新节点插入列表的末尾

New表示新添加的节点。 D是前一条尾巴。当将new添加到列表的末尾时，它将成为新的尾部，并且D将指向new。

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：addAtEnd()和display()。
addAtEnd()会将节点添加到列表的末尾：
1. 它首先检查head是否为空(空列表)，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. 如果列表不为空，则新添加的节点将成为新的尾部，而先前的尾部将指向新节点作为其下一个节点。新的尾巴将指向头部。
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current再次指向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 to the end of the list.
  def addAtEnd(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("Adding nodes to the end of the list: ");
        #Prints each node by incrementing pointer.
        print(current.data),
        while(current.next != self.head):
            current = current.next;
            print(current.data),
        print("\n");
 
class CircularLinkedList:
    cl = CreateList();
    #Adding 1 to the list
    cl.addAtEnd(1);
    cl.display();
    #Adding 2 to the list
    cl.addAtEnd(2);
    cl.display();
    #Adding 3 to the list
    cl.addAtEnd(3);
    cl.display();
    #Adding 4 to the list
    cl.addAtEnd(4);
    cl.display();

输出：

Adding nodes to the end of the list: 
1
Adding nodes to the end of the list: 
1 2
Adding nodes to the end of the list: 
1 2 3
Adding nodes to the end of the 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 addAtEnd(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("Adding nodes to the end of the list: \n");
         do{
             //Prints each node by incrementing pointer.
            printf("%d ", current->data);
            current = current->next;
        }while(current != head);
        printf("\n");
    }
}
    
int main()
{
    //Adding 1 to the list
   addAtEnd(1);
   display();
   //Adding 2 to the list
   addAtEnd(2);
   display();
   //Adding 3 to the list
   addAtEnd(3);
   display();
   //Adding 4 to the list
   addAtEnd(4);
   display();
   
   return 0;
}

输出：

Adding nodes to the end of the list: 
1
Adding nodes to the end of the list: 
1 2
Adding nodes to the end of the list: 
1 2 3
Adding nodes to the end of the list: 
1 2 3 4

JAVA

public class InsertAtEnd {
    //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 addAtEnd(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 points 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("Adding nodes to the end of the 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) {
            InsertAtEnd cl = new InsertAtEnd();
            
            //Adding 1 to the list
            cl.addAtEnd(1);
            cl.display();
            //Adding 2 to the list
            cl.addAtEnd(2);
            cl.display();
            //Adding 3 to the list
            cl.addAtEnd(3);
            cl.display();
            //Adding 4 to the list
            cl.addAtEnd(4);
            cl.display();
        }
}

输出：

Adding nodes to the end of the list: 
1
Adding nodes to the end of the list: 
1 2
Adding nodes to the end of the list: 
1 2 3
Adding nodes to the end of the 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 addAtEnd(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 = head;
                if(head == null){
                    Console.WriteLine("List is empty");
                }
                else{
                    Console.WriteLine("Adding nodes to the end of the list: ");
                    do{
                        //Prints each node by incrementing pointer.
                        Console.Write(" "+ current.data);
                        current = current.next;
                    }while(current != head);
                    Console.WriteLine();
                }        
            }
        }
        
        public static void Main()
        {
            
        CreateList cl = new CreateList();
            
        //Adding 1 to the list
        cl.addAtEnd(1);
        cl.display();
        //Adding 2 to the list
        cl.addAtEnd(2);
        cl.display();
        //Adding 3 to the list
        cl.addAtEnd(3);
        cl.display();
        //Adding 4 to the list
        cl.addAtEnd(4);
        cl.display();
        }    
    }
}

输出：

Adding nodes to the end of the list: 
1
Adding nodes to the end of the list: 
1 2
Adding nodes to the end of the list: 
1 2 3
Adding nodes to the end of the 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;
        $this->tail = NULL;
    }
    //This function will add the new node at the end of the list.
    function addAtEnd($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 "Adding nodes to the end of the list: 
";
             do{
                echo(" $current->data");
                $current = $current->next;
            }while($current != $this->head);
            echo "
";
        }
    }   
}
$cl = new CreateList();
//Adding 1 to the list
$cl->addAtEnd(1);
$cl->display();
//Adding 2 to the list
$cl->addAtEnd(2);
$cl->display();
//Adding 3 to the list
$cl->addAtEnd(3);
$cl->display();
//Adding 4 to the list
$cl->addAtEnd(4);
$cl->display();
?>

输出：

Adding nodes to the end of the list: 
1
Adding nodes to the end of the list: 
1 2
Adding nodes to the end of the list: 
1 2 3
Adding nodes to the end of the list: 
1 2 3 4