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Program to create a singly linked list of n nodes and count the number of nodes
ExplanationIn this program, we need to create a singly linked list and count the nodes present in the list.
To accomplish this task, traverse through the list using node current which initially points to head. Increment current in such a way that current will point to its next node in each iteration and increment variable count by 1. In the end, the count will hold the value which denotes the number of nodes present in the list. Algorithm
SolutionPython
#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()));
Output: Nodes of singly linked list: 1 2 3 4 Count of nodes present in the list: 4 C
#include <stdio.h>
//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;
}
Output: 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());
}
}
Output: 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<T>{
public T data;
public Node<T> next;
public Node(T value) {
data = value;
next = null;
}
}
public class SinglyLinkedList<T>{
//Represent the head and tail of the singly linked list
public Node<T> head = null;
public Node<T> tail = null;
//addNode() will add a new node to the list
public void addNode(T data) {
//Create a new node
Node<T> newNode = new Node<T>(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<T> 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<T> 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<int> sList = new SinglyLinkedList<int>();
//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());
}
}
Output: Nodes of singly linked list: 1 2 3 4 Count of nodes present in the list: 4 PHP
<!DOCTYPE html>
<html>
<body>
<?php
//Represent a node of singly linked list
class Node{
public $data;
public $next;
function __construct($data){
$this->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 <br>");
return;
}
print("Nodes of singly linked list: <br>");
while($current != NULL) {
//Prints each node by incrementing pointer
print($current->data . " ");
$current = $current->next;
}
print("<br>");
}
}
$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());
?>
</body>
</html>
Output: Nodes of singly linked list: 1 2 3 4 Count of nodes present in the list: 4
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