Решение

class Solution {
    fun isPalindrome(x: Int): Boolean {
        if (x < 0 || (x % 10 == 0 && x != 0)) return false
        var a = x
        var r = 0
        while (a > r) {
            r = r * 10 + a % 10
            a /= 10
        }
        return a == r || a == r / 10
    }
}