added java Linked list

Author: prakashn27

Linked-Lists/LinkedList.java

@@ -0,0 +1,72 @@
+/*
+Linked List Implementation
+@author: [email protected]
+*/
+class Node {
+	int data;
+	Node next;
+	Node prev;
+
+	public Node() {
+
+		next = null;
+		prev = null;
+	}
+
+}
+class LinkedList {
+	Node head = new Node();
+	Node tail = new Node();
+
+	boolean insertFront(int newData) {
+		Node newNode = new Node();
+		newNode.data = newData;
+
+		if(head == null ) {
+			head = newNode;
+			tail = head;
+			return true;
+		}
+		else {
+			Node oldHead = head;
+			head = newNode;
+			head.next = oldHead;
+			oldHead.prev = head;
+			return true;
+		}
+	}
+
+	boolean insertTail(int newData) {
+		Node newNode = new Node();
+		newNode.data = newData;
+		if(head == null ) {
+			head = newNode;
+			tail = head;
+			return true;
+		}
+		else {
+			//Node oldTail = tail;
+			newNode.prev =  tail;
+			tail.next = newNode;
+			tail = newNode;
+			return true;
+		}
+	}
+	int delete(int data) {
+		return 0;
+	}
+	void printList(){
+		Node cur = head;
+		while(cur != null) {
+			System.out.println(cur.data);
+			cur = cur.next;
+		}
+	}
+	public static void main(String[] args) {
+		LinkedList ll = new LinkedList();
+		ll.insertFront(30);
+		ll.insertFront(20);
+		ll.insertFront(10);
+		ll.printList();
+	}
+}