Grokking the Coding Interview: Patterns for Coding Questions

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Solution: Problem Challenge 1: Reverse alternating K-element Sub-list

Problem Statement

Given the head of a LinkedList and a number ‘k’, reverse every alternating ‘k’ sized sub-list starting from the head.

If, in the end, you are left with a sub-list with less than ‘k’ elements, reverse it too.

Constraints:

The number of nodes in the list is n.
1 <= k <= n <= 5000
0 <= Node.val <= 1000

Solution

The problem follows the In-place Reversal of a LinkedList pattern and is quite similar to Reverse every K-element Sub-list. The only difference is that we have to skip ‘k’ alternating elements

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