Which of the following is false about a doubly linked list?

General
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which of the following is false about a doubly linked list?

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Which of the following is false about a doubly linked list?

Answer: To determine which statement is false about a doubly linked list, let’s first understand what a doubly linked list is and its key characteristics.

A doubly linked list is a type of linked list in which each node contains three fields:

  1. Data field: Stores the data.
  2. Next pointer: Points to the next node in the sequence.
  3. Previous pointer: Points to the previous node in the sequence.

Characteristics of a Doubly Linked List:

  1. Bidirectional Traversal: You can traverse the list in both forward and backward directions.
  2. Additional Memory Usage: Each node requires extra memory to store the previous pointer.
  3. Insertion and Deletion: Insertion and deletion operations are more complex compared to a singly linked list because you have to update two pointers (next and previous) for each node.
  4. Access Time: Accessing elements in a doubly linked list requires linear time, i.e., O(n), as you may need to traverse the list to find a specific element.

Now, let’s consider some statements about doubly linked lists and identify which one is false:

  1. A doubly linked list allows traversal in both directions.
  2. Each node in a doubly linked list contains a data field, a next pointer, and a previous pointer.
  3. Doubly linked lists use less memory than singly linked lists.
  4. Insertion and deletion of nodes in a doubly linked list require updating both next and previous pointers.

Analysis of Statements:

  1. True: This is one of the main features of a doubly linked list.
  2. True: Each node indeed contains these three fields.
  3. False: Doubly linked lists use more memory than singly linked lists because each node contains an additional pointer (the previous pointer).
  4. True: Insertion and deletion operations require updating both the next and previous pointers.

Therefore, the statement that is false about a doubly linked list is:
3. Doubly linked lists use less memory than singly linked lists.

In reality, doubly linked lists use more memory due to the additional pointer in each node.