LinkedList Palindrome check file added

happysiva-mm · web-flow · commit 37668d73724c · 2020-10-02T12:33:22.000+05:30
Please review Thanks !
diff --git a/PalindromeList.java b/PalindromeList.java
@@ -0,0 +1,87 @@
+public class PalindromeList{
+    public static void main(String[] args){
+
+        MyNode root = MyNode.getSampleList();
+        System.out.println("Original List");
+        MyNode.display(root);
+        System.out.println("Is the list palindrome ? "+isPalindrome(root));
+
+    }
+
+    private static boolean isPalindrome(MyNode root){
+
+        MyNode fastPointer = root;
+        MyNode slowPointer = root;
+
+        while(fastPointer!=null){
+            fastPointer = fastPointer.next;
+            if(fastPointer!=null){
+                fastPointer= fastPointer.next;
+            }
+            slowPointer = slowPointer.next;
+        }
+
+        MyNode starting = root;
+        MyNode comparingNode = reverseList(slowPointer);
+
+        while(comparingNode!=null){
+            if(comparingNode.data != starting.data){
+                return false;
+            }
+            comparingNode = comparingNode.next;
+            starting = starting.next;
+        }
+
+        return true;
+
+    }
+
+    private static MyNode reverseList(MyNode root){
+
+        MyNode current = root;
+        MyNode next = null;
+        MyNode prev = null;
+
+        while(current!=null){
+            next = current.next;
+            current.next = prev;
+            prev = current;
+            current = next;
+        }
+
+        return prev;
+
+    }
+}
+
+class MyNode{
+
+    public int data ;
+    public MyNode next ;
+
+    MyNode(int data){
+        this.data = data;
+    }
+
+    protected static MyNode getSampleList(){
+        MyNode root = new MyNode(1);
+        root.next = new MyNode(2);
+        root.next.next = new MyNode(3);
+        root.next.next.next = new MyNode(3);
+        root.next.next.next.next = new MyNode(2);
+        root.next.next.next.next.next = new MyNode(1);
+        //root.next.next.next.next.next.next = new MyNode(3);
+        return root;
+    }
+
+    protected static void display(MyNode root){
+
+        MyNode temp = root;
+        while(temp!=null){
+            System.out.print(temp.data+" ");
+            temp = temp.next;
+        }
+        System.out.println();
+
+    }
+}
