{"id":5233,"date":"2021-09-23T10:37:48","date_gmt":"2021-09-23T10:37:48","guid":{"rendered":"https:\/\/www.prepbytes.com\/blog\/?p=5233"},"modified":"2022-11-18T06:56:54","modified_gmt":"2022-11-18T06:56:54","slug":"delete-a-doubly-linked-list-node-at-a-given-position","status":"publish","type":"post","link":"https:\/\/prepbytes.com\/blog\/delete-a-doubly-linked-list-node-at-a-given-position\/","title":{"rendered":"Delete a Doubly Linked List node at a given position"},"content":{"rendered":"

\"\"<\/p>\n

Introduction<\/h3>\n

In this article, we will discuss how to delete a doubly linked list node at a given position. Linked List is one of the most important topics for the interview of big tech giants like Samsung, Amazon, SquadStack, and lots more. In a coding interview, having a thorough understanding of Linked Lists might be a major benefit. Let\u2019s move to our topic of how to delete a doubly linked list node at a given position<\/p>\n<\/p>\n

Problem Statement<\/h3>\n

Given a doubly linked list and a position N<\/strong>. Our task is to delete the node of the doubly linked list at a given position N<\/strong> from the beginning.<\/p>\n

Problem Statement Understanding For doubly linked list deletion at specific position <\/h3>\n

According to the problem statement, we will be given a doubly linked list and a position N<\/strong>; we have to delete the node present at the N<\/strong>th<\/sup> position from the beginning. <\/p>\n

Note:<\/strong> We will take 1 based indexing in this problem.<\/p>\n

Let’s understand this problem using some examples:<\/p>\n

If the given doubly linked list is: <\/p>\n

\"\"<\/p>\n

and N<\/strong> = 2<\/p>\n

    \n
  • According to the problem statement, we need to delete the node present at position N<\/strong>th<\/sup> from the given doubly linked list.<\/li>\n
  • As we can see in the above example, the node present at position 2 is 8, which needs to be deleted.<\/li>\n
  • So after deleting the node at position 2, the resultant linked list will be:<\/li>\n<\/ul>\n

    \"\"<\/p>\n

    Let’s see another example:<\/p>\n

    If the given doubly linked list is: 1 \u2190\u2192 2 \u2190\u2192 4 \u2190\u2192 5 \u2190\u2192 7 \u2190\u2192 8 and N<\/strong> = 3<\/p>\n

      \n
    • In this case, we can see that the node present at 3rd<\/sup> position is the node with value 4. So we need to delete this node.<\/li>\n
    • So after deleting the node at position 3, the resultant linked list will be 1 \u2190\u2192 2 \u2190\u2192 5 \u2190\u2192 7 \u2190\u2192 8.<\/li>\n<\/ul>\n

      Now I think from the above examples, the problem is clear. So let\u2019s see how we can approach it.<\/p>\n

      Before moving to the approach section, try to think about how you can approach this problem.<\/p>\n

        \n
      • If stuck, no problem, we will thoroughly see how we can approach this problem in the next section.<\/li>\n<\/ul>\n

        Let\u2019s move to the approach section.<\/p>\n

        Approach To Delete A Doubly Linked List node at a given position<\/h3>\n

        The approach will be straightforward. <\/p>\n

          \n
        • We will start traversing through the list and the moment we reached the correct position i.e. the given position N<\/strong>, we will delete that node and connect its previous node with its next node.<\/li>\n<\/ul>\n

          Let’s move to the algorithm section to see the approach in more depth with some corner cases.<\/p>\n

          Algorithm To Delete A Doubly Linked List node at a given position<\/h3>\n
            \n
          • If the head of the list is NULL, that means the list is empty or if N<\/strong>next), now the next node of <\/strong>del has become <\/strong>pointer_to_head** node.\n
              \n
            • Check if the node to be deleted is not the first node, then update next of the previous node of del del->prev->next = del->next<\/strong>.<\/li>\n
            • Also check, if the node to be deleted is not the last, then update the prev pointer of the next node of del del->next->prev = del->prev<\/strong> and delete the del<\/strong> node.<\/li>\n<\/ul>\n<\/li>\n
            • Finally, output the desired linked list.<\/li>\n<\/ul>\n

              Dry Run To Delete A Doubly Linked List node at a given position<\/h3>\n

              \"\"
              \n\"\"<\/p>\n

              Code Implementation To Delete A Doubly Linked List node at a given position:<\/h3>\n\t\t\t\t\t\t