O(n)

class Solution:
    def isPalindrome(self, x: int) -> bool:
        s = str(x)
        size = int(len(s))

        for i in range(int(size/2)):
            if s[i] != s[-i-1]:
                return False

        return True

def main():
    s = Solution()

    print(s.isPalindrome(121)) # True
    print(s.isPalindrome(-121)) # False
    print(s.isPalindrome(10)) # False

if __name__ == '__main__':
    main()