RandomizeNumberArray3.java

import java.util.*;

public class RandomizeNumberArray3 {

    /**
    *       Program:        RandomizeNumberArray3.java
    *       Purpose:        Randomize order of array of contiguous integers
    *       Creator:        Chris Clarke
    *       Created:        10.05.2015
    */

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int min = 0; // makes the range from 0 to max-1
        int max = 0;
        Integer[] unshuffled;
        Integer[] shuffled;

        System.out.println("*** Randomize Number Array ***");
        System.out.print("Enter size of the array: ");

        try {
            max = scan.nextInt();
            unshuffled = new Integer[max];
        } catch (Exception x) {
            System.out.println("Not a positive whole number!");
            return;
        } // end try/catch

        System.out.print("Enter initial value (0 or 1): ");
        try {
            min = scan.nextInt();
        } catch (Exception x) {
            System.out.println("Not a positive whole number!");
            return;
        } // end try/catch

        // initialise the array
        for (int i=0; i<max; i++)
            unshuffled[i] = i + min;

        // function call to randomize the array
        shuffled = randomize(unshuffled, min, max);

        System.out.println(Arrays.toString(shuffled));

    } // main()

    public static Integer[] randomize(Integer[] unshuffled, int min, int max) {
        // randomize the order of an array of linear values

        Integer[] shuffled;
        List<Integer> li = new ArrayList<Integer>();
        li = Arrays.asList(unshuffled);
        Collections.shuffle(li);
        shuffled = new Integer[max];
        for (int i=0; i<li.size(); i++)
            shuffled[i] = li.get(i);

        return shuffled;

    } // randomize()

} // class RandomizeNumberArray3