Reverse K Nodes in Linked List | Dataford Interview Questions

How would you reverse every k nodes in a linked list?

Implement reverse_k_group(head, k) using constant extra space. The input is a singly linked list and a positive integer k; return the modified head, leaving a final group smaller than k unchanged. For [1,2,3,4,5] with k = 2, return [2,1,4,3,5]; for k = 3, return [3,2,1,4,5].

Constraints

0 <= number of nodes <= 5000
1 <= k <= 5000
Node values are integers
The input list is singly linked
A final group with fewer than k nodes must not be reversed

Function Signature

def reverse_k_group(head, k):

Your question is Reverse K Nodes in Linked List. Start with the requirements in the Question tab.

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Problem

How would you reverse every k nodes in a linked list?

Constraints

0 <= number of nodes <= 5000
1 <= k <= 5000
Node values are integers
The input list is singly linked
A final group with fewer than k nodes must not be reversed

Function Signature

def reverse_k_group(head, k):

Your question is Reverse K Nodes in Linked List. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.