Sort.java

import static java.lang.Math.pow;
import static java.lang.System.nanoTime;
import java.util.Arrays;
import java.util.ArrayList;
import java.util.Random;

public class Sort {
    public static int[] bubbleSort(int[] array) {
	int comparisons, swaps;
	comparisons = swaps = 0;
	for (int i = 0; i < array.length - 1; i++) {
	    for (int j = 1; j < array.length - i; j++) {
		comparisons++;
		if (array[j] < array[j - 1]) {
		    int temp = array[j];
		    array[j] = array[j - 1];
		    array[j - 1] = temp;
		    swaps++;
		}
	    }
	}
	System.out.println(Arrays.toString(array) + "\nComparisons: " + comparisons + "\nSwaps: " + swaps);
	return array;
    }
	
    public static int[] radixSort(int[] array) {
	//@SuppressWarnings(value = "unchecked")
	ArrayList<Integer>[] buckets = new ArrayList[10];
	for (int i = 0; i < 10; i++) {buckets[i] = new ArrayList<Integer>();} //Sort of generic array creation. This will still generate unchecked warnings but each ArrayList will be type Integer.
		
	int maximum = array[0];
	for (int i = 1; i < array.length; i++) {if (array[i] > maximum) {maximum = array[i];}}
	byte max = -1;
	for (; maximum > 0; maximum /= 10) {max++;} //A while loop would work but one-line code FTW.
	//   ^ Yes, that is valid.
		
	for (byte i = 0; i <= max; i++) {
	    for (int j = 0; j < array.length; j++) {
		if (array[j] < (int) pow(10, i)) {buckets[0].add(array[j]);}
		else {buckets[(array[j] / (int) pow(10, i)) % 10].add(array[j]);}
	    }
	    int index = 0;
	    for (byte j = 0; j < 10; j++) {
		for (int k = 0; k < buckets[j].size(); k++) {
		    array[index] = buckets[j].get(k);
		    index++;
		}
		buckets[j].clear();
	    }
	}
	return array;
    }

    public static int[] insertionSort(int[] array) {
	int comparisons = 0, assignments = 0;
	for (int i = 1; i < array.length; i++) {
	    int temp = array[i], j = i;
	    assignments += 2;
	    while ((j > 0) && (array[j - 1] > temp)) {
		comparisons++;
		array[j] = array[j - 1];
		assignments++;
		j--;
	    }
	    array[j] = temp;
	    assignments++;
	}
	System.out.println(Arrays.toString(array) + "\nComparisons: " + comparisons + "\nAssignments: " + assignments);
	return array;
    }

    public static int[] selectionSort(int[] array) {
	int comparisons = 0, assignments = 0;
	for (int i = 0; i < array.length - 1; i++) {
	    int indexOfMinimum = i;
	    assignments++;
	    for (int j = i + 1; j < array.length; j++) {
		comparisons++;
		if (array[j] < array[indexOfMinimum]) {
		    indexOfMinimum = j;
		    assignments++;
		}
	    }
	    int temp = array[i];
	    array[i] = array[indexOfMinimum];
	    array[indexOfMinimum] = temp;
	    assignments += 3;
	}
	System.out.println(Arrays.toString(array) + "\nComparisons: " + comparisons + "\nAssignments: " + assignments);
	return array;
    }

    public static int[] randomIntArray(int length, int max) {
	int[] array = new int[length];
	Random random = new Random();
	for (int i = 0; i < length; i++) {array[i] = random.nextInt(max);}
	return array;
    }
	
    public static void main(String[] args) {
	int[] array = randomIntArray(100, 100);
	long t1, t2;
	t1 = nanoTime();
	bubbleSort(array);
	t2 = nanoTime();
	System.out.println("Time: " + (t2 - t1) + " ns / " + ((double) (t2 - t1) / 1000000) + " ms / " + ((double) (t2 - t1) / 1000000000) + " s");
	System.out.println();
	t1 = nanoTime();
	System.out.println(Arrays.toString(radixSort(array)));
	t2 = nanoTime();
	System.out.println("Time: " + (t2 - t1) + " ns / " + ((double) (t2 - t1) / 1000000) + " ms / " + ((double) (t2 - t1) / 1000000000) + " s");
    }
}