Question

Given a singly linked list implementation of a list, what is the worst-case time complexity for the following operations (assume that the implementation only maintains a reference to the head of the linked list):

Retrieving an item at an arbitrary index from the middle of the list.

Answer 1

Retrieving an item at a random index in a singly linked list has a worst-case time complexity of O(n), as it may require traversing the entire list.

Step-by-step explanation:

The worst-case time complexity for retrieving an item at an arbitrary index from the middle of a singly linked list is O(n). Since the linked list only maintains a reference to the head, to retrieve an item at a given index, you need to traverse the list from the head node one element at a time until you reach the desired index. This means you'll have to visit potentially every node in the list if the item is towards the end, leading to a linear time complexity, which is denoted as O(n), where n is the number of elements in the list. It's important to note that this is considered the worst-case scenario, as retrieving an element from the beginning of the list (i.e., the head) can be done in constant time, O(1).