Java-Programs/PalindromeList.java at master · codeankit10/Java-Programs · GitHub

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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();

}

Java-Programs/PalindromeList.java at master · codeankit10/Java-Programs · GitHub

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