[Leet Code] 234. Palindrome Linked List

Palindrome Linked List

 

 문제 설명

 

Given the head of a singly linked list, return true if it is a palindrome.

 

 제한 사항

 

• The number of nodes in the list is in the range [1, 105].
• 0 <= Node.val <= 9

 

 입출력 예

 

Example 1:

Input: head = [1,2,2,1]
Output: true

 

Example 2:

Input: head = [1,2]
Output: false

 

 Python 코드

 

Python code 

class Solution:
    def isPalindrome(self, head: ListNode) -> bool:
        val_list = []
        curr = head
        while curr:
            val_list.append(curr.val)
            curr = curr.next
        return val_list == val_list[::-1]

 

* 참고 링크 : https://ceuity.tistory.com/12

https://velog.io/@jayb/LeetCode-234.Palindrome-Linked-List%ED%8C%B0%EB%A6%B0%EB%93%9C%EB%A1%AC-%EC%97%B0%EA%B2%B0-%EB%A6%AC%EC%8A%A4%ED%8A%B8

 C++ 코드

 

C ++  code

class Solution {
public:
    bool isPalindrome(ListNode* head) {
        ListNode *slow = head, *fast = head, *prev, *temp;
        while (fast && fast->next)
            slow = slow->next, fast = fast->next->next;
        prev = slow, slow = slow->next, prev->next = NULL;
        while (slow)
            temp = slow->next, slow->next = prev, prev = slow, slow = temp;
        fast = head, slow = prev;
        while (slow)
            if (fast->val != slow->val) return false;
            else fast = fast->next, slow = slow->next;
        return true;
    }
};

 

* 참고 링크 : https://dev.to/seanpgallivan/solution-palindrome-linked-list-5721

 

 출처

 

https://leetcode.com/problems/palindrome-linked-list/submissions/