19. Remove Nth Node From End of List
Given the head of a linked list, remove the nth node from the end of the list and return its head.
Example 1:
Input: head = [1,2,3,4,5], n = 2 Output: [1,2,3,5]
Example 2:
Input: head = [1], n = 1 Output: []
Example 3:
Input: head = [1,2], n = 1 Output: [1]
Constraints:
- The number of nodes in the list is
sz. 1 <= sz <= 300 <= Node.val <= 1001 <= n <= sz
Follow up: Could you do this in one pass?
Asked at 18 companies
Google
TCSTopics
Hints open one at a time
Hint 1
Maintain two pointers and update one with a delay of n steps.
Loading editor…
1# Definition for singly-linked list.
2# class ListNode:
3# def __init__(self, val=0, next=None):
4# self.val = val
5# self.next = next
6class Solution:
7 def removeNthFromEnd(self, head: Optional[ListNode], n: int) -> Optional[ListNode]:
8
Starter codePython 3Spaces: 4
Loading editor…
1# Definition for singly-linked list.
2# class ListNode:
3# def __init__(self, val=0, next=None):
4# self.val = val
5# self.next = next
6class Solution:
7 def removeNthFromEnd(self, head: Optional[ListNode], n: int) -> Optional[ListNode]:
8
Starter codePython 3Spaces: 4
Examples
Input
[1,2,3,4,5] 2
Input
[1] 1
Input
[1,2] 1
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