[LeetCode][Python3] 19. Remove Nth Node From End of List

Problem :

https://leetcode.com/problems/remove-nth-node-from-end-of-list

My Solution :

# Definition for singly-linked list.

# class ListNode:

# def __init__(self, x):

# self.val = x

# self.next = None

class Solution:

def removeNthFromEnd(self, head, n):

"""

:type head: ListNode

:type n: int

:rtype: ListNode

"""

first = second = dummy = ListNode(0)

dummy.next = head

for _ in range(n):

first = first.next

while first and first.next:

first = first.next

second = second.next

second.next = second.next.next

return dummy.next

Comment :

Cracking the Coding Interview 책에서 봤던 문제라 별 고민 없이 two pointer 전략으로 접근하였다. Linked List는 항상 Edge Case 때문에 고생하는데 dummy head를 활용하는게 일종의 트릭이 될 수 있다.