Remove Nth Node From End of List
Created: August 20, 2018 by [lek-tin]
Last updated: August 20, 2018
Given a linked list, remove the n-th node from the end of list and return its head.
Example
Given linked list: 1->2->3->4->5, and n = 2.
After removing the second node from the end, the linked list becomes 1->2->3->5.
Note
Given n will always be valid.
Follow-up
Could you do this in one pass?
Solution
# Definition for singly-linked list.
# class ListNode(object):
# def __init__(self, x):
# self.val = x
# self.next = None
class Solution(object):
def removeNthFromEnd(self, head, n):
"""
:type head: ListNode
:type n: int
:rtype: ListNode
"""
start = ListNode(0)
slow = start
fast = start
slow.next = head
# let fast move n steps forward
for i in range(n+1):
fast = fast.next
while fast != None:
slow = slow.next
fast = fast.next
slow.next = slow.next.next
return start.next