Linked List is a linear data structure. Linked list elements are not stored at a contiguous location, the elements are linked using pointers. Singly Linked list is the collection of nodes, where each node has two parts one is the data and other is the linked part.
Example:
Input : AddNodes = {2, 3, 4}
Output: LinkedList = [2, 3, 4]
Size = 3
Input : AddNodes = {1, 2, 3, 4, 5}
Output: LinkedList = [1, 2, 3, 4, 5]
Size = 5
Operations:
- Create Node linked list
- Define methods like addNode(),displayNodes() and countNodes()
- Get the final answer
Implementation:
Java
// Java Program to Create a Singly Linked List// of n Nodes and Count the Number of Nodesimport java.io.*;import java.util.*;public class LinkedListCreation { class Node { int data; Node next; // constructor to create new node Node(int data) { this.data = data; this.next = null; } } // Initially both head and tail are not // pointing to any other node Node head = null; Node tail = null; // method to add newNode in Linked List void addNode(int data) { 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 { tail.next = newNode; // storing newnode in tail tail = newNode; } } // display linked list void displayNodes() { Node current = head; if (head == null) { System.out.println("Empty"); return; } System.out.println("Nodes : "); while (current != null) { System.out.print(current.data + " "); current = current.next; } System.out.println(); } // method to count nodes int countNodes() { // Initially zero int count = 0; Node currentNode = head; // iterate until all the nodes are present while (currentNode != null) { count++; currentNode = currentNode.next; } // return the count return count; } public static void main(String[] args) { LinkedListCreation L1 = new LinkedListCreation(); L1.addNode(1); L1.addNode(2); L1.addNode(3); L1.addNode(4); // Displays the nodes present in the list L1.displayNodes(); // Counts the nodes present in the given list System.out.println("Total Nodes: " + L1.countNodes()); }} |
Output
Nodes : 1 2 3 4 Total Nodes: 4
Time Complexity For new node Insertion:
- At first: O(1)
- At End: O(N), where N is the size of linked list
Time Complexity For count number of nodes: O(N), where N is a number of nodes
Auxiliary space: O(1) as it is using constant space
