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Abhishek Chaudhary
Abhishek Chaudhary

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Rotate List

Given the head of a linked list, rotate the list to the right by k places.

Example 1:

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

Example 2:

Input: head = [0,1,2], k = 4
Output: [2,0,1]

Constraints:

  • The number of nodes in the list is in the range [0, 500].
  • -100 <= Node.val <= 100
  • 0 <= k <= 2 * 109

SOLUTION:

# Definition for singly-linked list. # class ListNode: # def __init__(self, val=0, next=None): # self.val = val # self.next = next class Solution: def rotateRight(self, head: Optional[ListNode], k: int) -> Optional[ListNode]: if not head: return head curr = head n = 1 while curr and curr.next: curr = curr.next n += 1 k = k % n curr.next = head curr = head for i in range(n - k - 1): curr = curr.next head = curr.next curr.next = None return head 
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