Sunbelt Computer Software

PL/B Language Development and Support

algorithm/leetcode/isPalindrome.py at master · ugaemi/algorithm · GitHub

20 lines (16 loc) · 503 Bytes

class ListNode:

def __init__(self, val=0, next=None):

self.val = val

self.next = next

class Solution:

def isPalindrome(self, head: ListNode) -> bool:

rev = None

slow = fast = head

while fast and fast.next:

fast = fast.next.next

rev, rev.next, slow = slow, rev, slow.next

if fast:

slow = slow.next

while rev and rev.val == slow.val:

slow, rev = slow.next, rev.next

return not rev