Page 341 - AP Computer Science A, 7th edition

public class Deck {
private int[] deck;
public static final int NUMCARDS = 52;
/∗ ∗ constructor ∗ / public Deck()
{
deck = new int[NUMCARDS];
for (int i = 0; i < NUMCARDS; i++)
}
deck[i] = i;
/∗ ∗
public void writeDeck() {
∗ /
for (int card : deck) System.out.print(card + “ ”);
System.out.println();
System.out.println(); }
/∗ ∗
private void swap(int[] arr, int i, int j) {
int temp = arr[i]; arr[i] = arr[j]; arr[j] = temp;
}
/∗∗ Shuffle Deck: Generate a random permutation by picking a
∗ random card from those remaining and putting it in the
∗ next slot, starting from the right.
∗/
public void shuffle() {
int index;
for (int i = NUMCARDS – 1; i > 0; i--) {
//generate an int from 0 to i
index = (int) (Math.random() ∗ (i + 1)); swap(deck, i, index);
Write contents of Deck.
Swap arr[i] and arr[j] in array arr.
∗ /