feat: Implement circular linked list and Add insert, delete and displ…

…ay methods

JavaDsaWithTest/src/main/java/org/practice/dsa/linkedlist/CircularLinkedList.java

@@ -0,0 +1,73 @@
+package org.practice.dsa.linkedlist;
+
+public class CircularLinkedList {
+
+    private Node head;
+    private Node tail;
+
+    public CircularLinkedList() {
+        this.head = null;
+        this.tail = null;
+    }
+
+    public void insert(int val) {
+        Node node = new Node(val);
+        if (head == null) {
+            head = node;
+            tail = node;
+            return;
+        }
+        tail.next = node;
+        node.next = head;
+        tail = node;
+    }
+
+    public void display() {
+        Node node = head;
+        if (head != null) {
+            do {
+                System.out.print(node.val + "->");
+                if (node.next != null) {
+                    node = node.next;
+                }
+            } while (node != head);
+        }
+        System.out.println("HEAD");
+    }
+
+    public void delete(int val) {
+        Node node = head;
+        if (node == null) {
+            return;
+        }
+
+        if (head == tail) {
+            head = null;
+            tail = null;
+            return;
+        }
+
+        if (node.val == val) {
+            head = head.next;
+            tail.next = head;
+        }
+
+        do {
+            Node n = node.next;
+            if (n.val == val) {
+                node.next = n.next;
+                break;
+            }
+            node = node.next;
+        } while (node != head);
+    }
+
+    private class Node {
+        int val;
+        Node next;
+
+        public Node(int val) {
+            this.val = val;
+        }
+    }
+}

JavaDsaWithTest/src/main/java/org/practice/dsa/linkedlist/CircularMain.java

@@ -0,0 +1,21 @@
+package org.practice.dsa.linkedlist;
+
+public class CircularMain {
+    public static void main(String[] args) {
+        CircularLinkedList cll = new CircularLinkedList();
+
+        cll.insert(10);
+        cll.insert(11);
+        cll.insert(12);
+        cll.insert(13);
+        cll.insert(14);
+        cll.insert(15);
+
+        cll.display();
+
+        cll.delete(12);
+        cll.delete(13);
+
+        cll.display();
+    }
+}