palindrome in LL

Author: ANUKULJHA1506

Love Babbar DSA Sheet Solutions/LinkedList/palindrome_in_ll.cpp

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+// 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;
+}
+// This code has been contributed by Striver