From 6cd8f4cfa7849c0027817b23bb9c5d7c0c9f4286 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sas=CC=8Ca=20Kocic=CC=81?= <sasa.kocic@yogaeasy.de>
Date: Thu, 18 Jun 2020 19:19:21 +0200
Subject: [PATCH] Implemented Fisher-Yates shuffle()

---
 src/CardGame.java     | 30 ++++++++++++++++++++----------
 src/CardGameTest.java |  2 +-
 src/Pile.java         | 20 --------------------
 src/Player.java       | 20 ++------------------
 4 files changed, 23 insertions(+), 49 deletions(-)

diff --git a/src/CardGame.java b/src/CardGame.java
index e5f9001..d8b53b7 100644
--- a/src/CardGame.java
+++ b/src/CardGame.java
@@ -1,9 +1,7 @@
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Random;
 
-import static java.util.Collections.shuffle;
-//import org-apache-commons-lang3.ArrayUtils;
-
 public class CardGame {
     public Player[] players;
     Pile pot;
@@ -15,21 +13,21 @@ public class CardGame {
      */
     public CardGame(int numberOfCards, int numberOfPlayers) {
         Pile deck = createDeck(numberOfCards);
-        shuffle(deck, new Random());
+        shuffleArray(deck);
         this.players = new Player[numberOfPlayers];
         draws = new Card[numberOfPlayers];
-        int deckCount = deck.count();
+        int cardsPerPlayer = deck.size() / numberOfPlayers;
         for (int i = 0; i < numberOfPlayers; i++) {
-            players[i] = new Player(String.valueOf(i), deck.getCardsForPlayer(deckCount / numberOfPlayers));
+            players[i] = new Player(String.valueOf(i), deck.getCardsForPlayer(cardsPerPlayer));
         }
         pot = new Pile();
     }
 
     public Pile createDeck(int numberOfCards) {
         Pile deck = new Pile();
-        for (int number = 0; number < numberOfCards; number++) {
+        for (int number = 1; number <= numberOfCards; number++) {
             for (Card.Suit suit: Card.Suit.values()) {
-                deck.add(new Card(number + 1, suit));
+                deck.add(new Card(number, suit));
             }
         }
         return deck;
@@ -43,7 +41,7 @@ public class CardGame {
 
     private void round() {
         for (int i = 0; i < draws.length; i++) {
-            if (!players[i].broke()) {
+            if (players[i].cardsCount() > 0) {
                 System.out.printf("Player %d (%d cards): ", i, players[i].cardsCount());
                 draws[i] = players[i].draw();
                 System.out.printf("%d - %s\n", draws[i].number, draws[i].suit);
@@ -53,7 +51,6 @@ public class CardGame {
             }
         }
         processWinner(draws);
-
     }
 
     private void processWinner(Card[] drawn) {
@@ -85,4 +82,17 @@ public class CardGame {
         }
         return true;
     }
+
+    /**
+     * Fisher-Yates shuffle()
+     * https://stackoverflow.com/questions/1519736/random-shuffling-of-an-array
+     */
+    private static void shuffleArray(Pile pile)
+    {
+        Random random = new Random();
+        for (int i = pile.size() - 1; i > 0; i--)
+        {
+            Collections.swap(pile, i, random.nextInt(i + 1));
+        }
+    }
 }
diff --git a/src/CardGameTest.java b/src/CardGameTest.java
index 9c3b46a..75d515c 100644
--- a/src/CardGameTest.java
+++ b/src/CardGameTest.java
@@ -16,7 +16,7 @@ class CardGameTest {
     void createDeck() {
         assertEquals(2, cardGame.players.length);
         for (int i = 0; i < 2; i++) {
-            assertEquals(20, cardGame.players[i].drawPile.count());
+            assertEquals(20, cardGame.players[i].drawPile.size());
         }
     }
 
diff --git a/src/Pile.java b/src/Pile.java
index e42b692..e1c1d99 100644
--- a/src/Pile.java
+++ b/src/Pile.java
@@ -1,27 +1,11 @@
 import java.util.ArrayList;
 
 public class Pile extends ArrayList<Card> {
-//    ArrayList<Card> pile = new ArrayList<Card>();
-
-//    public Boolean isEmpty() {
-//        return pile.isEmpty();
-//    }
-//
-//    public void shuffle() {
-//    }
-//
-    public void takeDiscarded() {
-    }
-
     public void addAll(Card[] cards) {
         for(Card card: cards)
             add(card);
     }
 
-    public int count() {
-        return size();
-    }
-
     public Pile getCardsForPlayer(int number) {
         Pile cardsForPlayer = new Pile();
         for (int i = 0; i < number; i++) {
@@ -30,8 +14,4 @@ public class Pile extends ArrayList<Card> {
         }
         return cardsForPlayer;
     }
-
-//    public void add(Card card) {
-//        pile.add(card);
-//    }
 }
diff --git a/src/Player.java b/src/Player.java
index 75b9335..0e4744e 100644
--- a/src/Player.java
+++ b/src/Player.java
@@ -21,14 +21,6 @@ public class Player {
         return discardPile;
     }
 
-    public void setDrawPile(Pile drawPile) {
-        this.drawPile = drawPile;
-    }
-
-    public void setDiscardPile(Pile discardPile) {
-        this.discardPile = discardPile;
-    }
-
     public Card draw() throws NoMoreCardsException {
         if (getDrawPile().isEmpty()) {
             if (getDiscardPile().isEmpty()) {
@@ -38,7 +30,7 @@ public class Player {
             drawPile.addAll(discardPile);
             discardPile.clear();
         }
-        if (drawPile.count() > 0) {
+        if (drawPile.size() > 0) {
             Card draw = drawPile.get(0);
             drawPile.remove(0);
             return draw;
@@ -46,15 +38,7 @@ public class Player {
         return null;
     }
 
-    public boolean broke() {
-        return drawPile.isEmpty() && discardPile.isEmpty();
-    }
-
-    public void addPot(Card[] draws) {
-        discardPile.addAll(draws);
-    }
-
     public int cardsCount() {
-        return drawPile.count() + discardPile.count();
+        return drawPile.size() + discardPile.size();
     }
 }