[LeetCode] Palindrome Number

문제

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 a palindrome while 123 is not.

정수 x가 주어지면 x가 회문 정수이면 true를 반환합니다. 정수는 정방향과 역방향이 같을 때 회문입니다.
예를 들어, 121은 회문이지만 123은 그렇지 않습니다.

 

Example

Example 1:

Input: x = 121
Output: true
Explanation: 121 reads as 121 from left to right and from right to left.

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.

 

Constraints:

• -231 <= x <= 231 - 1

---

풀이

/**
 * @param {number} x
 * @return {boolean}
 */
var isPalindrome = function(x) {
  return x === +((x + '').split('').reverse().join(''));
};

• 뒤집어서 같으면 true, 아니면 false
• Runtime: 176ms ~ 304ms
• Memory: 48.4MB ~ 42.2MB