Leetcode —— Palindrome Number


Given an integer x, return true if x is palindrome integer.

An integer is a palindrome when it reads the same backward as forward. For example, 121 is palindrome while 123 is not.

Example 1:

Input: x = 121
Output: true

Example 2:

Input: x = -121
Output: false
Explanation: From left to right, it reads -121. From right to left, it becomes 121-. Therefore it is not a palindrome.

Example 3:

Input: x = 10
Output: false
Explanation: Reads 01 from right to left. Therefore it is not a palindrome.

Example 4:

Input: x = -101
Output: false


# @param {Integer} x
# @return {Boolean}
def is_palindrome(x)
    x = x.to_s
    x.reverse == x

用 Ruby 内置的 String 的 reverse 可以很方便的实现回文的判断