Introduction to In-Place Manipulation of a Linked List

About the pattern

The in-place manipulation of a linked list pattern allows us to modify a linked list without using any additional memory. In-place refers to an algorithm that processes or modifies a data structure using only the existing memory space, without requiring additional memory proportional to the input size. This pattern is best suited for problems where we need to modify the structure of the linked list, i.e., the order in which nodes are linked together. For example, some problems require a reversal of a set of nodes in a linked list which can extend to reversing the whole linked list. Instead of making a new linked list with reversed links, we can do it in place without using additional memory.

The naive approach to reverse a linked list is to traverse it and produce a new linked list with every link reversed. The time complexity of this algorithm is $O(n)$ ...