Sorter.java

import java.io.*;
import java.util.*;

public class Sorter{

    private ArrayList[] buckets = new ArrayList[10];
    private int[] nums;
    private int digits, size;
    Random r = new Random();

//Default Constructor (ten 4-digit integers)
    public Sorter(){
        nums = new int[10];
        for (int i = 0; i<10; i++)
         nums[i] = r.nextInt(10000);
        digits = 4;
        size = 10;
    }

//Custom Constructor (s d-digit integers)
    public Sorter(int d, int s){
        digits = d;
        size = s;
        nums = new int[size];
        int range = 1;
        for (int j = 0; j<digits; j++)
         range = range * 10;
        for (int i = 0; i<size; i++)
         nums[i] = r.nextInt(range);
    }

    public String toString() {
        return Arrays.toString(nums);
    }

    public void arrange(){
        for (int a=0; a<10; a++)
        	buckets[a] = new ArrayList();
        for (int b = 0; b<digits;b++){
        	for (int c = 0; c<nums.length; c++){
            	int z = nums[c];
              	for (int d=b; d>0; d--)
                	z = z/10;
                z = z%10;
                buckets[z].add(nums[c]);
         	}
         	for(int e=0; e<nums.length; e++){
                for (int f=0; f<buckets.length;f++) {
                	if (buckets[f].size() != 0) {
                        nums[e] = (Integer) buckets[f].get(0);
                        buckets[f].remove(0);
                        f = buckets.length;
                 	}
                }
         	}
		}
    }

}