decreprsenior

package com.paper;

import java.util.Arrays;
import java.util.Collections;
import java.util.List;

public class decreprsenior {
public static void main (String[] args){
decreprsenior test = new decreprsenior();
System.out.println(test.solution(353));
System.out.println(test.solution(1000000001));
}
public int solution (int n){
if (n > 1_000_000_000){
return -1;
}

Integer[] digits = new Integer[Integer.toString(n).length()];


for (int i = 0; i < digits.length; i++){
digits[i] = n % 10;
n = n/10;
}
List<Integer> digitslist = Arrays.asList(digits);
Collections.sort(digitslist);

int maxvalue = 0;
for (int j = digitslist.size() ; j > 0; j-- ){
maxvalue = maxvalue + digitslist.get(j-1);
maxvalue = maxvalue * 10;
}
return maxvalue / 10;
}
}