LeetCode 풀기 - 19. Remove Nth Node From End of List

19. Remove Nth Node From End of List

https://leetcode.com/problems/remove-nth-node-from-end-of-list/discuss/?currentPage=1&orderBy=most_votes&query= 

Remove Nth Node From End of List - LeetCode Discuss

 

문제)

솔루션1)

스택 자료구조를 사용한다.

모든 노드를 순회하면서 스택에 노드를 추가하고 n번 만큼 pop()수행해서 삭제 대상 노드를 찾는다.

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, val=0, next=None):
#         self.val = val
#         self.next = next
class Solution:
    def removeNthFromEnd(self, head: Optional[ListNode], n: int) -> Optional[ListNode]:
        node = head
        stack = deque()
        while node:
            stack.append(node)
            node = node.next
        
        for i in range(n-1):
            stack.pop()
        
        target_node = stack[-1]
        if len(stack) == 1:
            head = target_node.next
        else:
            prev_target_node = stack[-2]
            prev_target_node.next = target_node.next
        
        return head