class Solution:

# Time: O(log10(n)) - process half the digits

# Space: O(1)

def is_palindrome(self, x: int) -> bool:

# Negative numbers and numbers ending in 0 (except 0 itself) are not palindromes

if x < 0 or (x % 10 == 0 and x != 0):

return False

reversed_half = 0

while x > reversed_half:

reversed_half = reversed_half * 10 + x % 10

x //= 10

# Even length: x == reversed_half

# Odd length: x == reversed_half // 10 (drop middle digit)

return x == reversed_half or x == reversed_half // 10