A Common-Sense Guide to Data Structures and Algorithms

Deletion

Deletion is very similar to insertion in terms of efficiency. To delete a node from the beginning of a linked list, all we need to do is perform one step: we change the first_node of the linked list to now point to the second node.

Let’s return to our example of the linked list containing the values "once", "upon", "a", and "time". If we wanted to delete the value "once", we would simply change the linked list to begin at "upon":

list.first_node = node_2

Contrast this with an array in which deleting the first element means shifting all remaining data one cell to the left, an efficiency of O(N).

When it comes to deleting the final node of a linked list, the actual deletion takes one step—we just take the second-to-last node and make ...