How to sort Integer digits in ascending order without Strings or Arrays?

Question

I\'m trying to sort the digits of an integer of any length in ascending order without using Strings, arrays or recursion.

Example:

Input: 451467
Outp         


        

Answer 1

class SortDigits {
    public static void main(String[] args) {
        int inp=57437821;
        int len=Integer.toString(inp).length();
        int[] arr=new int[len];
        for(int i=0;i<len;i++)
        {
            arr[i]=inp%10;
            inp=inp/10;
        }
        Arrays.sort(arr);
        int num=0;
        for(int i=0;i<len;i++)
        {
            num=(num*10)+arr[i];
        }
        System.out.println(num);
    }    
}

Answer 2

I assume you're allowed to use hashing.

public static void sortDigits(int x) {
    Map<Integer, Integer> digitCounts = new HashMap<>();

    while (x > 0) {
        int digit = x % 10;
        Integer currentCount = digitCounts.get(digit);
        if (currentCount == null) {
            currentCount = 0;
        }
        digitCounts.put(x % 10, currentCount + 1);
        x = x / 10;
    }

    for (int i = 0; i < 10; i++) {
        Integer count = digitCounts.get(i);
        if (count == null) {
            continue;
        }
        for (int j = 0; j < digitCounts.get(i); j++) {
            System.out.print(i);
        }
    }
}