Package g0001_0100.s0025_reverse_nodes_in_k_group

Class Solution

  • public class Solution
extends Object
    25 - Reverse Nodes in k-Group.

    Hard

    Given a linked list, reverse the nodes of a linked list k at a time and return its modified list.

    k is a positive integer and is less than or equal to the length of the linked list. If the number of nodes is not a multiple of k then left-out nodes, in the end, should remain as it is.

    You may not alter the values in the list’s nodes, only nodes themselves may be changed.

    Example 1:

    Input: head = [1,2,3,4,5], k = 2

    Output: [2,1,4,3,5]

    Example 2:

    Input: head = [1,2,3,4,5], k = 3

    Output: [3,2,1,4,5]

    Example 3:

    Input: head = [1,2,3,4,5], k = 1

    Output: [1,2,3,4,5]

    Example 4:

    Input: head = [1], k = 1

    Output: [1]

    Constraints:

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

    Follow-up: Can you solve the problem in O(1) extra memory space?

    • Constructor Detail

      • Solution

        public Solution()