### Problem: Reverse Nodes in K Group Reverse every k nodes of a given linked list, where k is a positive integer. #### Problem Statement Given the head of a linked list and an integer k, reverse every k nodes of the linked list in-place. The nodes from index i to i+k-1 should form a reversed group. The original list should still be accessible and usable during the process, with all elements correctly linked after reversing every k nodes. This modification does not change the overall length of the list. #### Rules and Constraints - k is a positive integer, k >= 1. - The elements in the linked list do not contain duplicate values. - The nodes in the linked list are uniquely identifiable by their values. - Time complexity: O(n) where n is the total number of nodes in the linked list. - Space complexity: O(1), which implies that we only use a constant amount of space during the operation. Note: This problem can be solved in-place, without modifying the original list or creating a new linked list. ### Example **Input:** {"head":[1,2,3,4,5],"k":2} **Output:** [2,1,4,3,5]