[leetcode 234] Palindrom Linked List

LeetCode-234

Palindrome Linked List : 주어진 head가 palindrome인지 아닌지

note : range : 1~10^5

MyAnswer

        :::python

# Definition for singly-linked list.
# class ListNode:
#     def init(self, val=0, next=None):
#         self.val = val
#         self.next = next
class Solution:
    def isPalindrome(self, head: Optional[ListNode]) -> bool:
        temp: List = []
        if not head:
            return True
        node = head
        while node is not None:
            temp.append(node.val)
            node = node.next
        if len(temp)%2==0:
            return temp[:len(temp)//2] == temp[(len(temp)//2):][::-1]
        else:
            return temp[:len(temp)//2] == temp[(len(temp)//2)+1:][::-1]

Result : 855ms Memory: 46.6mb

Answer

        :::python

# Definition for singly-linked list.
# class ListNode:
#     def init(self, val=0, next=None):
#         self.val = val
#         self.next = next
class Solution:
    def isPalindrome(self, head: Optional[ListNode]) -> bool:        
        q: Deque = collections.deque()
        if not head:
            return True
        node = head
        while node is not None:
            q.append(node.val)
            node = node.next
        while len(q) > 1:
            if q.popleft()!=q.pop():
                return False
        return True

Result : 775ms Memory: 47.5mb