Reverse Linked List II

Reverse Linked List II

Given the head of a singly linked list and two integers left and right where left <= right, reverse the nodes of the list from position left to position right, and return the reversed list.

Positions are 1-indexed.

Examples

Example 1:

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

Example 2:

Input: head = [5], left = 1, right = 1
Output: [5]

Constraints

• The number of nodes in the list is n.
• 1 <= n <= 500
• -500 <= Node.val <= 500
• 1 <= left <= right <= n

Expected Complexity

• Time: O(n)
• Space: O(1)