{"id":4696,"date":"2021-09-03T11:22:04","date_gmt":"2021-09-03T11:22:04","guid":{"rendered":"https:\/\/www.prepbytes.com\/blog\/?p=4696"},"modified":"2023-07-27T12:30:40","modified_gmt":"2023-07-27T12:30:40","slug":"check-if-a-doubly-linked-list-of-characters-is-palindrome-or-not","status":"publish","type":"post","link":"https:\/\/prepbytes.com\/blog\/check-if-a-doubly-linked-list-of-characters-is-palindrome-or-not\/","title":{"rendered":"Check if a doubly-linked list of characters is palindrome or not"},"content":{"rendered":"

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Doubly linked lists exhibit versatility as a data structure, facilitating bidirectional traversal and seamless insertion and deletion of elements. They prove invaluable in diverse programming scenarios, providing elegant solutions to numerous challenges. An intriguing problem that commonly arises is determining whether a doubly linked list of characters forms a palindrome.<\/p>\n

A palindrome is a sequence of characters that reads the same forwards and backwards. When dealing with doubly linked lists, this concept extends to checking whether the list remains unchanged when traversed in both directions, forming a palindrome-like structure.
\nLet’s look into our problem \u201cHow to check doubly linked list of character is palindrome?\u201d<\/p>\n

How To Check Palindrome In Doubly Linked List<\/h3>\n

This question is relatively straightforward. We need to verify whether the given doubly linked list of characters is a palindrome or not. A list is considered a palindrome if it reads the same both backward and forward.<\/p>\n

Input:<\/strong><\/p>\n

\"\"<\/p>\n

Output:<\/strong> Palindrome<\/p>\n

Explanation:<\/strong> The given list of characters is palindrome.<\/p>\n

We can use the two-pointers method to solve this. Can you guess why we are using the two-pointers method? Yes, with the help of this method, we can solve this problem by only doing a single traversal of the given list. This approach is going to take O(n) time. Let us have a glance at the approach.<\/p>\n

Approach For Checking Palindrome In Doubly Linked List<\/h3>\n

As mentioned earlier, we are going to use the two pointers technique here. We will create two pointers, left<\/em> and right<\/em>. The left pointer will point at the head of the list, while the right pointer will point at the end of the list. To make the right pointer point to the end of the list, we will make it initially point to the head. Then, we will increment it till we reach the end of the list.<\/p>\n

Now, we have a clear idea about the approach for palindrome words list, let\u2019s see the algorithm for implementing \u201cHow to check doubly linked list of character is palindrome?<\/p>\n

Algorithm To Check Palindrome In Doubly Linked List<\/h3>\n
    \n
  • Initialize two pointers, left and right. Left will point at the head of the list and right will point at the tail of the list.<\/li>\n
  • To make the right pointer point to the tail of the list, first, make it point to the head. Then, traverse till the end and keep increasing the right pointer. In the end, it will point at the tail.<\/li>\n
  • Compare the values at the left node and the right node. If they are equal, then increment the left pointer and decrement the right pointer till the middle of the given list.<\/li>\n
  • If, at any point, the value at the left node is not equal to the value at the right node, return false.<\/li>\n
  • In the end, return true.<\/li>\n<\/ul>\n

    Dry Run To Check Palindrome In Doubly Linked List<\/h3>\n

    \"\"<\/p>\n

    Code Implementation To Check If characters is Palindrome in Doubly Linked List<\/h4>\n\t\t\t\t\t\t