Package g0001_0100.s0025_reverse_nodes_in_k_group

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    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?

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final ListNode reverseKGroup(ListNode head, Integer k)

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait