Chapter 11 Exercise 7, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

11.7  (Shuffle ArrayList)
Write the following method that shuffles the elements in an ArrayList of integers.
public static void shuffle(ArrayList<Integer> list)

import java.util.ArrayList;

public class Exercise_07 {

    public static void main(String[] args) {

        ArrayList<Integer> list = new ArrayList<>();

        for (int i = 0; i < 100; i++) {
            list.add(i);
        }

        System.out.println(list);

        System.out.println("Shuffling list...");
        shuffle(list);
        System.out.println(list);
    }

    public static void shuffle(ArrayList<Integer> list) {

        // simple solution
        //Collections.shuffle(list);

        // manual shuffle
        for (int i = 0; i < list.size(); i++) {
            int randomIndex = (int) (Math.random() * list.size());
            int temp = list.get(randomIndex);
            list.set(randomIndex, list.get(i));
            list.set(i, temp);
        }

    }


}