9. Palindrome Number.js

/*  TIME COMPLEXITY IS O(1) */

/*
    https://leetcode.com/problems/palindrome-number/discuss/2396146/100-fastest-solution-explained-with-java-script-o1

*/

/*
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.
 
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. 
*/

/**
 * @param {number} x
 * @return {boolean}
 */
var isPalindrome = function (x) {
    var rev = x.toString().split("").reverse().join("");    //-121
    var ans = false;
    if (x == rev) {
        ans = true;
    }
    return ans;
};
console.log(isPalindrome(-121));