📜  数据结构示例-创建N个节点单链表与计数

📅  最后修改于: 2020-10-15 01:44:49             🧑  作者: Mango

程序创建n个节点的单链接列表并计算节点数

说明

在此程序中,我们需要创建一个单链接列表并计算列表中存在的节点。

要完成此任务,请使用最初指向head的节点current遍历列表。以这样的方式增加电流,即电流将在每次迭代中指向其下一个节点,并将变量count增加1。最后,该计数将保留一个值,该值表示列表中存在的节点数。

算法

  • 创建一个具有两个属性的类Node:data和next。下一个是指向列表中下一个节点的指针。
  • 创建另一个具有两个属性的类:head和tail。
  • addNode()将向列表添加一个新节点:
    1. 创建一个新节点。
    2. 它首先检查head是否等于null,这意味着列表为空。
    3. 如果列表为空,头和尾都将指向新添加的节点。
    4. 如果列表不为空,则新节点将被添加到列表的末尾,使得尾部的下一个将指向新添加的节点。这个新节点将成为列表的新尾部。
  • countNodes()将计算列表中存在的节点:
    1. 定义一个节点电流,该电流将初始指向列表的开头。
    2. 声明并将变量计数初始化为0。
    3. 遍历列表直到当前点为null。
    4. 对于列表中遇到的每个节点,将count的值增加1。
  • display()将显示列表中存在的节点:
    1. 定义一个节点电流,该电流将初始指向列表的开头。
    2. 遍历列表,直到当前指向null。
    3. 通过在每次迭代中使电流指向其旁边的节点来显示每个节点。

示例:

Python

#Represent a node of the singly linked list
class Node:
    def __init__(self,data):
        self.data = data;
        self.next = None;
        
class CountNodes:
    #Represent the head and tail of the singly linked list
    def __init__(self):
        self.head = None;
        self.tail = None;
        
    #addNode() will add a new node to the list
    def addNode(self, data):
        #Create a new node
        newNode = Node(data);
        
        #Checks if the list is empty
        if(self.head == None):
            #If list is empty, both head and tail will point to new node
            self.head = newNode;
            self.tail = newNode;
        else:
            #newNode will be added after tail such that tail's next will point to newNode
            self.tail.next = newNode;
            #newNode will become new tail of the list
            self.tail = newNode;
            
    #countNodes() will count the nodes present in the list
    def countNodes(self):
        count = 0;
        #Node current will point to head
        current = self.head;
        
        while(current != None):
            #Increment the count by 1 for each node
            count = count + 1;
            current = current.next;
        return count;
    
    #display() will display all the nodes present in the list
    def display(self):
        #Node current will point to head
        current = self.head;
        
        if(self.head == None):
            print("List is empty");
            return;
        print("Nodes of singly linked list: ");
        while(current != None):
            #Prints each node by incrementing pointer
            print(current.data),
            current = current.next;
     
 
sList = CountNodes();
        
#Add nodes to the list
sList.addNode(1);
sList.addNode(2);
sList.addNode(3);
sList.addNode(4);
 
#Displays the nodes present in the list
sList.display();
 
#Counts the nodes present in the given list
print("Count of nodes present in the list: " + str(sList.countNodes()));

输出:

 Nodes of singly linked list: 
1 2 3 4 
Count of nodes present in the list: 4

C

#include 
 
//Represent a node of singly linked list
struct node{
    int data;
    struct node *next;
};    
 
//Represent the head and tail of the singly linked list
struct node *head, *tail = NULL;
 
//addNode() will add a new node to the list
void addNode(int data) {
    //Create a new node
    struct node *newNode = (struct node*)malloc(sizeof(struct node));
    newNode->data = data;
    newNode->next = NULL;
    
    //Checks if the list is empty
    if(head == NULL) {
        //If list is empty, both head and tail will point to new node
        head = newNode;
        tail = newNode;
    }
    else {
        //newNode will be added after tail such that tail's next will point to newNode
        tail->next = newNode;
        //newNode will become new tail of the list
        tail = newNode;
    }
}
 
//countNodes() will count the nodes present in the list
int countNodes() {
    int count = 0;
    //Node current will point to head
    struct node *current = head;
    
    while(current != NULL) {
        //Increment the count by 1 for each node
        count++;
        current = current->next;
    }
    return count;
}
    
//display() will display all the nodes present in the list
void display() {
    //Node current will point to head
    struct node *current = head;
    
    if(head == NULL) {
        printf("List is empty\n");
        return;
    }
    printf("Nodes of singly linked list: \n");
    while(current != NULL) {
        //Prints each node by incrementing pointer
        printf("%d ", current->data);
        current = current->next;
    }
    printf("\n");
}
    
int main()
{
    //Add nodes to the list
    addNode(1);
    addNode(2);
    addNode(3);
    addNode(4);
    
    //Displays the nodes present in the list
    display();
    
    //Counts the nodes present in the given list
    printf("Count of nodes present in the list: %d", countNodes());
 
    return 0;
}

输出:

Nodes of singly linked list: 
1 2 3 4 
Count of nodes present in the list: 4

Java

public class CountNodes {
    
    //Represent a node of singly linked list
    class Node{
        int data;
        Node next;
        
        public Node(int data) {
            this.data = data;
            this.next = null;
        }
    }
 
    //Represent the head and tail of the singly linked list
    public Node head = null;
    public Node tail = null;
    
    //addNode() will add a new node to the list
    public void addNode(int data) {
        //Create a new node
        Node newNode = new Node(data);
        
        //Checks if the list is empty
        if(head == null) {
            //If list is empty, both head and tail will point to new node
            head = newNode;
            tail = newNode;
        }
        else {
            //newNode will be added after tail such that tail's next will point to newNode
            tail.next = newNode;
            //newNode will become new tail of the list
            tail = newNode;
        }
    }
    
    //countNodes() will count the nodes present in the list
    public int countNodes() {
        int count = 0;
        //Node current will point to head
        Node current = head;
        
        while(current != null) {
            //Increment the count by 1 for each node
            count++;
            current = current.next;
        }
        return count;
    }
        
    //display() will display all the nodes present in the list
    public void display() {
        //Node current will point to head
        Node current = head;
        if(head == null) {
            System.out.println("List is empty");
            return;
        }
        System.out.println("Nodes of singly linked list: ");
        while(current != null) {
            //Prints each node by incrementing pointer
            System.out.print(current.data + " ");
            current = current.next;
        }
        System.out.println();
    }
    
    public static void main(String[] args) {
        
        CountNodes sList = new CountNodes();
        
        //Add nodes to the list
        sList.addNode(1);
        sList.addNode(2);
        sList.addNode(3);
        sList.addNode(4);
        
        //Displays the nodes present in the list
        sList.display();
        
        //Counts the nodes present in the given list
        System.out.println("Count of nodes present in the list: " + sList.countNodes());
    }
}

输出:

Nodes of the singly linked list:
1 2 3 4 
Count of nodes present in the list: 4

C#

using System;
                    
public class CountNodes
{
    //Represent a node of singly linked list
    public class Node{
        public T data;
        public Node next;
        
        public Node(T value) {
            data = value;
            next = null;
        }
    }
        
    public class SinglyLinkedList{
        //Represent the head and tail of the singly linked list
        public Node head = null;             
         public Node tail = null;
    
        //addNode() will add a new node to the list
        public void addNode(T data) {
            //Create a new node
            Node newNode = new Node(data);
 
            //Checks if the list is empty
            if(head == null) {
                //If list is empty, both head and tail will point to new node
                head = newNode;
                tail = newNode;
            }
            else {
                //newNode will be added after tail such that tail's next will point to newNode
                tail.next = newNode;
                //newNode will become new tail of the list
                tail = newNode;
            }
        }
        
        //countNodes() will count the nodes present in the list
        public int countNodes() {
            int count = 0;
            //Node current will point to head
            Node current = head;
 
            while(current != null) {
                //Increment the count by 1 for each node
                count++;
                current = current.next;
            }
            return count;
        }
        
        //display() will display all the nodes present in the list
        public void display() {
            //Node current will point to head
            Node current = head;
            
            if(head == null) {
                Console.WriteLine("List is empty");
                return;
            }
            Console.WriteLine("Nodes of singly linked list: ");
            while(current != null) {
                //Prints each node by incrementing pointer
                Console.Write(current.data + " ");
                current = current.next;
            }
            Console.WriteLine();
        }
    }
    
    public static void Main()
    {
        SinglyLinkedList sList = new SinglyLinkedList();
        
        //Add nodes to the list
        sList.addNode(1);
        sList.addNode(2);
        sList.addNode(3);
        sList.addNode(4);
        
        //Displays the nodes present in the list
        sList.display();    
        
        //Counts the nodes present in the given list
        Console.WriteLine("Count of nodes present in the list: " + sList.countNodes());
    }
}

输出:

Nodes of singly linked list: 
1 2 3 4 
Count of nodes present in the list: 4

PHP




data = $data;
        $this->next = NULL;
    }
}
class CountNodes{
    //Represent the head and tail of the singly linked list
    public $head;
    public $tail;
    function __construct(){
        $this->head = NULL;
        $this->tail = NULL;
    }
    
    //addNode() will add a new node to the list
    function addNode($data) {
        //Create a new node
        $newNode = new Node($data);
        
        //Checks if the list is empty
        if($this->head == NULL) {
            //If list is empty, both head and tail will point to new node
            $this->head = $newNode;
            $this->tail = $newNode;
        }
        else {
            //newNode will be added after tail such that tail's next will point to newNode
            $this->tail->next = $newNode;
            //newNode will become new tail of the list
            $this->tail = $newNode;
        }
    }
    
    //countNodes() will count the nodes present in the list
    function countNodes() {
        $count = 0;
        //Node current will point to head
        $current = $this->head;
        
        while($current != NULL) {
            //Increment the count by 1 for each node
            $count++;
            $current = $current->next;
        }
        return $count;
    }    
    
    //display() will display all the nodes present in the list
    function display() {
        //Node current will point to head
        $current = $this->head;
        
        if($this->head == NULL) {
            print("List is empty 
"); return; } print("Nodes of singly linked list:
"); while($current != NULL) { //Prints each node by incrementing pointer print($current->data . " "); $current = $current->next; } print("
"); } } $sList = new CountNodes(); //Add nodes to the list $sList->addNode(1); $sList->addNode(2); $sList->addNode(3); $sList->addNode(4); //Displays the nodes present in the list $sList->display(); //Counts the nodes present in the given list print("Count of nodes present in the list: " . $sList->countNodes()); ?>

输出:

Nodes of singly linked list: 
1 2 3 4 
Count of nodes present in the list: 4