Palindrome List in CPP

// C++ program to implement

// the above approach

#include<bits/stdc++.h>

using namespace std; 

 

class Node 

{

    public:

    int data;

    Node(int d)

    {

        data = d;

    }

    Node *ptr;

};

 

// Function to check if the linked list 

// is palindrome or not 

bool isPalin(Node* head)

{        

    // Temp pointer 

    Node* slow= head;

 

    // Declare a stack 

    stack <int> s; 

 

    // Push all elements of the list 

    // to the stack 

    while(slow != NULL)

    {

        s.push(slow->data);

 

        // Move ahead 

        slow = slow->ptr;

    }

 

    // Iterate in the list again and 

    // check by popping from the stack

    while(head != NULL )

    {            

        // Get the top most element 

        int i=s.top();

 

        // Pop the element 

        s.pop();

 

        // Check if data is not

        // same as popped element 

        if(head -> data != i)

        {

            return false;

        }

 

        // Move ahead 

        head=head->ptr;

        }

        return true;

}

 

// Driver Code 

int main()

{

    // Addition of linked list 

    Node one =  Node(1);

    Node two = Node(2);

    Node three = Node(3);

    Node four = Node(2);

    Node five = Node(1);

 

    // Initialize the next pointer

    // of every current pointer 

    five.ptr = NULL;

    one.ptr = &two;

    two.ptr = &three;

    three.ptr = &four;

    four.ptr = &five;

    Node* temp = &one;

 

     

    // Call function to check 

    // palindrome or not 

    int result = isPalin(&one);

   

    if(result == 1)

            cout << "isPalindrome is true";

    else

        cout << "isPalindrome is true";

 

    return 0;

}