Mid/SeniorLinked List
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.
Example 1
[1] -> [2] -> [3] -> [4] -> [5] -> null --- [1] -> [4] -> [3] -> [2] -> [5] -> null
Input
head = [1,2,3,4,5], left = 2, right = 4Output
[1,4,3,2,5]The nodes from positions 2 through 4 are reversed, changing 2 -> 3 -> 4 into 4 -> 3 -> 2.
Example 2
[5] -> null --- [5] -> null
Input
head = [5], left = 1, right = 1Output
[5]There is only one node, so reversing positions 1 through 1 leaves the list unchanged.
Constraints
- The number of nodes in the list is n
- 1 <= n <= 500
- -500 <= Node.val <= 500
- 1 <= left <= right <= n