Added program to implement custom linked list

Programs/Circular Integer LinkedList/Main.java → Programs/LinkedList/Circular Integer LinkedList/Main.java

@@ -1,24 +1,24 @@
-public class Main {
-	
-	public static void main(String[] args) {
-		circularLinkedList list = new circularLinkedList();
-
-		/**adds 10 random number in linkedlist */
-		for(int i=0;i<10;i++){
-			int number = (int)(Math.random()*10);
-			list.add(number);
-		}
-		System.out.println("linkedlist:");
-		list.print();
-		System.out.println("size of linkedlist: "+list.size());
-		System.out.println("\n");
-
-		list.delete(1);
-		list.delete(0);
-		
-		System.out.println("1. element is : "+list.getElement(1));
-		System.out.println("head of linkedlist is: "+list.getElement(0));
-		
-	}
-	
-}
+public class Main {
+
+	public static void main(String[] args) {
+		circularLinkedList list = new circularLinkedList();
+
+		/**adds 10 random number in linkedlist */
+		for(int i=0;i<10;i++){
+			int number = (int)(Math.random()*10);
+			list.add(number);
+		}
+		System.out.println("linkedlist:");
+		list.print();
+		System.out.println("size of linkedlist: "+list.size());
+		System.out.println("\n");
+
+		list.delete(1);
+		list.delete(0);
+
+		System.out.println("1. element is : "+list.getElement(1));
+		System.out.println("head of linkedlist is: "+list.getElement(0));
+
+	}
+
+}

Programs/Circular Integer LinkedList/Node.java → Programs/LinkedList/Circular Integer LinkedList/Node.java

@@ -1,19 +1,19 @@
-public class Node {
-	int data;
-	Node next;
-	
-	public Node(int a) {
-		data=a;
-		next=null;
-		
-	}
-	
-	public Node() {
-		data=-1;
-		next=null;
-	}
-
-	public int getNodeElement(){
-		return data;
-	}
-}
+public class Node {
+	int data;
+	Node next;
+
+	public Node(int a) {
+		data=a;
+		next=null;
+
+	}
+
+	public Node() {
+		data=-1;
+		next=null;
+	}
+
+	public int getNodeElement(){
+		return data;
+	}
+}

Programs/Circular Integer LinkedList/circularLinkedList.java → Programs/LinkedList/Circular Integer LinkedList/circularLinkedList.java

@@ -1,112 +1,112 @@
-public class circularLinkedList {
-	Node head;
-	int size;
-	
-	public circularLinkedList() {
-		head=new Node();
-		head.next=head;
-		size=0;
-		head.data=-1;
-	}
-	/**
-	 * adds a new element end of the linkedlist
-	 * @param num
-	 */
-	public void add(int num) {
-		
-		Node newNode=new Node(num);
-		Node currNode=head;
-		
-		if(size==0)
-		{
-			head.data=num;
-		}
-		else {
-			while(!currNode.next.equals(head))
-			{
-				currNode=currNode.next;
-				
-			}
-			newNode.next=currNode.next;
-			currNode.next=newNode;
-		}
-		size++;
-			
-	}
-	
-	/**
-	 * deletes index 
-	 * index 0 is equal to head of linkedlist
-	 * @param index
-	 */
-	public void delete(int index) {
-
-		Node currNode=head;
-		Node currNodePrev=head;
-		
-		if(size==0)
-			System.out.println("Linkedlist is empty");
-		if(index>=size)
-			System.out.println("index of deletion is larger then size of linkedlist");
-		else{
-			if(index==0){
-				while(!currNode.next.equals(head)){
-					currNode=currNode.next;
-				}
-				currNode.next=head.next;
-				head=head.next;
-			}else{
-				for(int i=0;i<index;i++){
-					currNodePrev=currNode;
-					currNode=currNode.next;
-				}
-				currNodePrev.next=currNode.next;
-				currNode=null;
-			}
-		}
-		System.out.println("after deletion of "+index+". element :");
-		print();
-	}
-	/**
-	 * prints linkedlist 
-	 * 
-	 */
-	public void print() {
-		System.out.print(head.data+" ");
-		Node currNode=head.next;
-		
-		while(!currNode.equals(head)) {
-			System.out.print(currNode.data+" ");
-			currNode=currNode.next;
-		}
-		System.out.println();
-		
-		
-	}
-	/**
-	 * returns size of linked list
-	 * @return integer size
-	 */
-	public int size(){
-		return size;
-	}
-	
-	/**
-	 * returns element of given index
-	 * 0 is denotes head node
-	 * @param index
-	 * @return
-	 */
-	public int getElement(int index){
-		Node currNode=head;
-		for(int i=0;i<index;i++){
-			currNode=currNode.next;
-		}
-		return currNode.getNodeElement();
-	}
-	
-	
-}
-
-
-
+public class circularLinkedList {
+	Node head;
+	int size;
+
+	public circularLinkedList() {
+		head=new Node();
+		head.next=head;
+		size=0;
+		head.data=-1;
+	}
+	/**
+	 * adds a new element end of the linkedlist
+	 * @param num
+	 */
+	public void add(int num) {
+
+		Node newNode=new Node(num);
+		Node currNode=head;
+
+		if(size==0)
+		{
+			head.data=num;
+		}
+		else {
+			while(!currNode.next.equals(head))
+			{
+				currNode=currNode.next;
+
+			}
+			newNode.next=currNode.next;
+			currNode.next=newNode;
+		}
+		size++;
+
+	}
+
+	/**
+	 * deletes index 
+	 * index 0 is equal to head of linkedlist
+	 * @param index
+	 */
+	public void delete(int index) {
+
+		Node currNode=head;
+		Node currNodePrev=head;
+
+		if(size==0)
+			System.out.println("Linkedlist is empty");
+		if(index>=size)
+			System.out.println("index of deletion is larger then size of linkedlist");
+		else{
+			if(index==0){
+				while(!currNode.next.equals(head)){
+					currNode=currNode.next;
+				}
+				currNode.next=head.next;
+				head=head.next;
+			}else{
+				for(int i=0;i<index;i++){
+					currNodePrev=currNode;
+					currNode=currNode.next;
+				}
+				currNodePrev.next=currNode.next;
+				currNode=null;
+			}
+		}
+		System.out.println("after deletion of "+index+". element :");
+		print();
+	}
+	/**
+	 * prints linkedlist 
+	 * 
+	 */
+	public void print() {
+		System.out.print(head.data+" ");
+		Node currNode=head.next;
+
+		while(!currNode.equals(head)) {
+			System.out.print(currNode.data+" ");
+			currNode=currNode.next;
+		}
+		System.out.println();
+
+
+	}
+	/**
+	 * returns size of linked list
+	 * @return integer size
+	 */
+	public int size(){
+		return size;
+	}
+
+	/**
+	 * returns element of given index
+	 * 0 is denotes head node
+	 * @param index
+	 * @return
+	 */
+	public int getElement(int index){
+		Node currNode=head;
+		for(int i=0;i<index;i++){
+			currNode=currNode.next;
+		}
+		return currNode.getNodeElement();
+	}
+
+
+}
+
+
+

Programs/LinkedList/CustomLinkedList.java

@@ -0,0 +1,86 @@
+package Programs.LinkedList;
+
+/* Program to implement simple int linked list from scratch */
+public class CustomLinkedList {
+  private Node Head;
+  private Node Tail;
+
+  private int size;
+  public CustomLinkedList() {
+    this.size = 0;
+  }
+
+  // Node class with private instance variables and constructors
+
+  class Node {
+    private int value;
+    private Node next;
+
+    public Node(int value) {
+      this.value = value;
+    }
+    public Node(int value, Node next) {
+      this.value = value;
+      this.next = next;
+    }
+
+  }
+
+  // insert method which takes the new value as parameter and inserts at the beginning
+
+  void insertFirst(int val) {
+    Node node = new Node(val);
+    node.next = Head;
+    Head = node;
+    if(Tail == null) {
+      Tail = Head;
+    }
+    size++;
+  }
+
+  // traverse method to print all the elements present
+
+  public void traverse() {
+
+    Node temp = Head;
+    while(temp != null) {
+      System.out.print(temp.value + "-> ");
+      temp = temp.next;
+    }
+    System.out.println("END");
+  }
+
+  // insertLast method to insert element at the end of the list
+
+  public void insertLast(int val) {
+    if(Tail == null) {
+      insertFirst(val);
+      return;
+    }
+    Node node = new Node(val);
+    Tail.next = node;
+    Tail = node;
+    size++;
+  }
+
+  // method to insert the given value at a given index
+
+  public void insertAtIndex(int val, int index) {
+    if(index == 0) {
+      insertFirst(val);
+      return;
+    }
+    if(index == size) {
+      insertLast(val);
+      return;
+    }
+    Node temp = Head;
+    for(int i = 1; i < index && index < size; i++) {
+      temp = temp.next;
+    }
+    Node node = new Node(val, temp.next);
+    temp.next = node;
+    size++;
+
+  }
+}