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1721. Swapping Nodes in a Linked List

MediumLinked List Preparing judge… LeetCode

You are given the head of a linked list, and an integer k.

Return the head of the linked list after swapping the values of the kth node from the beginning and the kth node from the end (the list is 1-indexed).

 

Example 1:

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

Example 2:

Input: head = [7,9,6,6,7,8,3,0,9,5], k = 5
Output: [7,9,6,6,8,7,3,0,9,5]

 

Constraints:

  • The number of nodes in the list is n.
  • 1 <= k <= n <= 105
  • 0 <= Node.val <= 100
Linked ListTwo Pointers

Hints

Hint 1
We can traverse the linked list and store the elements in an array.
Hint 2
Upon conversion to an array, we can swap the required elements by indexing the array.
Hint 3
We can rebuild the linked list using the order of the elements in the array.