Driver.java

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

public class Driver {
    public static void main (String[] args) {
		ArrayList[] buckets = new ArrayList[10];
		int n = 0, maxDigit = 3, numItems = 200000;
		String s = "";
		long start, end;
		
		// makes the arraylist that sorts the array
		for (int i = 0; i < 10; i++) {
		    buckets[i] = new ArrayList();
		}

		// makes the array of ints to be sorted
		int[] a = new int[numItems], b = new int[numItems], c = new int[numItems], d = new int[numItems];
		for (int i = 0; i < numItems; i++) {
		    Random r = new Random();
		    a[i] = r.nextInt((int)(Math.pow(10, maxDigit)));
		}
		b = a;
		c = a;
		d = a;

		//RADIX SORT
	        start = System.currentTimeMillis();
		while (n < maxDigit) {
		    for (int i = 0; i < numItems; i++) {
				int x =  (int)((a[i]/(Math.pow(10, n))) % 10);
				buckets[x].add(a[i]);
		    }
		    int[] newArray = new int[numItems];
		    int ArrayCount = 0;
		    for (int i = 0; i < 10; i++) {
				//i goes through the buckets and so buckets[i] is the list of items
				for (int x = 0; x < buckets[i].size(); x++){
				    //x goes through buckets[i] and adds each number to newArray
				    newArray[ArrayCount] = (Integer)buckets[i].get(x);
				    ArrayCount++;
				}
		    }
		    a = newArray;
		    for (int i = 0; i < 10; i++) {
				buckets[i] = new ArrayList();
		    }
		    n++;
		}
		end = System.currentTimeMillis();
		System.out.println(end - start);


		//BUILT IN SORT
		start = System.currentTimeMillis();
		Arrays.sort(b);
		end = System.currentTimeMillis();
		System.out.println(end - start);


		//BUBBLE SORT
		int len = c.length;
		int comps = 0, swaps = 0;
		start = System.currentTimeMillis();
		for (int i=0;i<len;i++) {
		    for (int j=0;j<len-1;j++) {
			comps ++;
			int left = c[j];
			int right = c[j+1];
			if (right > left) {
			    c[j] = right;
			    c[j+1] = left;
			    swaps ++;
			}
		    }
		}		
		end = System.currentTimeMillis();
		System.out.println(end- start);
		System.out.println(comps);
		System.out.println(swaps);


    }

}