A-level linked lists (video)

What is a key advantage of using linked lists over arrays?

• Linked lists require less memory than arrays

• Linked lists are easier to implement than arrays

• Linked lists allow for dynamic memory allocation

• Linked lists store data in a sorted manner

Answer explanation

A key advantage of linked lists is that they allow for dynamic memory allocation, meaning they can grow and shrink in size as needed, unlike arrays which have a fixed size. This flexibility is crucial for efficient memory management.

Which of the following is a common application of linked lists?

• Sorting data in ascending order

• Implementing a browser cache

• Creating a binary search tree

• Storing data in a fixed-size array

Answer explanation

Implementing a browser cache is a common application of linked lists because they allow efficient insertion and deletion of items, which is essential for managing the dynamic nature of cached data.

Which of the following statements about linked lists is accurate?

• Linked lists can only store integers.

• Linked lists are static data structures.

• Linked lists are always sorted.

• Linked lists can be used for polynomial addition.

Answer explanation

Linked lists can store various data types, including polynomials. They are dynamic structures, allowing efficient polynomial addition by linking terms, making the statement about polynomial addition accurate.

Which data structure can be implemented using linked lists?

• Only binary trees

• Only queues

• Stacks, trees, queues, and graphs

• Only arrays

Answer explanation

Linked lists can be used to implement various data structures, including stacks, trees, queues, and graphs. This flexibility allows for dynamic memory allocation and efficient insertions and deletions, making the correct choice 'Stacks, trees, queues, and graphs'.

What characteristic distinguishes linked lists from arrays?

• Linked lists do not require pointers

• Linked lists have a fixed size

• Linked lists store elements in contiguous memory

• Linked lists do not have a specific order for items

Answer explanation

Linked lists do not have a specific order for items, allowing for dynamic insertion and deletion. In contrast, arrays have a fixed size and store elements in contiguous memory, maintaining a specific order.

What is the primary role of pointers in a linked list?

• To sort the items in the list

• To allocate memory for the linked list

• To connect each item to the next item

• To store the data in a specific order

Answer explanation

The primary role of pointers in a linked list is to connect each item to the next item. This allows for dynamic memory allocation and efficient insertion and deletion of elements, unlike arrays which require contiguous memory.

How does the last item in a linked list indicate its position?

• It has no pointer at all

• It points to a null value or zero

• It points to the first item in the list

• It contains a special marker

Answer explanation

In a linked list, the last item indicates its position by pointing to a null value or zero. This signifies that there are no further elements in the list, distinguishing it from other nodes that point to subsequent items.

What does it mean to traverse a linked list?

• To rearrange the items in the list

• To delete items from the list

• To search for a specific item in the list

• To visit each item in the list using a pointer

Answer explanation

Traversing a linked list means to visit each item in the list using a pointer. This process allows you to access and potentially manipulate each node sequentially, which is essential for operations like searching or displaying the list.

What is the first step in traversing a linked list programmatically?

• Assign the value of the last item to a pointer

• Set a pointer variable to the start of the list

• Sort the items in the list

• Count the number of items in the list

Answer explanation

The first step in traversing a linked list is to set a pointer variable to the start of the list. This allows you to access each node sequentially, which is essential for any traversal operation.

In the context of linked lists, what does the term 'searching' refer to?

• Removing an item from the list

• Testing each item to find a specific one

• Finding the first item in the list

• Sorting the items in the list

Answer explanation

In linked lists, 'searching' means testing each item to find a specific one. This involves traversing the list and checking each element until the desired item is found, making it the correct choice.