Stanford CS106A Yahtzee Solution
Yahtzee! I just finished coding it, and couldn’t be happier. Can’t wait to finish the next 2 assignments 🙂 This class seems to be getting much easier since the Breakout game, which I think is a good thing!
Here is my solution to Yahtzee, which you can also find on github:
/*
* File: Yahtzee.java
* ------------------
* This program will eventually play the Yahtzee game.
*/
import acm.io.*;
import acm.program.*;
import acm.util.*;
import java.util.*;
public class Yahtzee extends GraphicsProgram implements YahtzeeConstants {
/* Private instance variables */
private int nPlayers; //number of players
private String[] playerNames; //an array of Player names
private YahtzeeDisplay display;
private RandomGenerator rgen = new RandomGenerator(); //random number generator
private int[] dieResults = new int [N_DICE]; //stores the most recently rolled dice numbers
private int[][] categoryScores; //stores the score for each category for each player
private int category; //selected category
private int[][] selectedCategories; //stores the already selected categories
public static void main(String[] args) {
new Yahtzee().start(args);
}
public void run() {
IODialog dialog = getDialog();
nPlayers = dialog.readInt("Enter number of players");
while(true) {
if(nPlayers <= MAX_PLAYERS) break;
nPlayers = dialog.readInt("You can only enter up to " + MAX_PLAYERS +" number of players. Enter number of players");
}
playerNames = new String[nPlayers];
categoryScores = new int [nPlayers + 1][N_CATEGORIES+1];
selectedCategories = new int[nPlayers+1][N_CATEGORIES+1];
for (int i = 1; i <= nPlayers; i++) {
playerNames[i - 1] = dialog.readLine("Enter name for player " + i);
}
display = new YahtzeeDisplay(getGCanvas(), playerNames);
playGame();
}
private void playGame() {
for(int i = 0; i < N_SCORING_CATEGORIES; i++) {
for(int j=1; j <= nPlayers; j++) {
initializeFirstRoll(j);
secondAndThirdRoll(j);
selectCategory(j);
}
}
calculateResults();
calculateWinner();
}
/* In the beginning of a players turn,
* the player clicks on "Roll Dice",
* the Dice results are displayed and
* stored in the diceResults array */
private void initializeFirstRoll(int playerNumber) {
for(int i = 0; i < N_DICE; i++) {
int dieRoll = rgen.nextInt(1,6);
dieResults[i] = dieRoll;
}
display.printMessage(playerNames[playerNumber - 1] + "'s turn! Click the " + ""Roll Dice" " + "button to roll the dice.");
display.waitForPlayerToClickRoll(playerNumber);
display.displayDice(dieResults);
}
/* For the second and third roll,
* the player selects the dice he or she wants to re-roll,
* the selected dice are re-rolled, and the new
* dice values are displayed and stored in the diceResults array */
private void secondAndThirdRoll(int playerNumber) {
for (int i = 0; i < 2; i++) {
display.printMessage("Select the dice you wish to re-roll and click " + ""Roll Again"");
display.waitForPlayerToSelectDice();
for(int j = 0; j < N_DICE; j++) {
if(display.isDieSelected(j) == true) {
int dieRoll = rgen.nextInt(1,6);
dieResults[j] = dieRoll;
}
}
display.displayDice(dieResults);
}
}
/* Pre-condition: The player has rolled the dice three times.
* The player selects the category for the dice.
* The player cannot select a category that he/she already chose in a previous turn.*/
private void selectCategory(int playerNumber) {
while(true) {
display.printMessage("Select a category for this roll");
category = display.waitForPlayerToSelectCategory();
if(selectedCategories[playerNumber][category] == 0) {
calculateCategoryScore(playerNumber);
break;
}
}
}
/* Pre-condition: The user selected a category he/she has not previously selected.
* Assigns 1 to the selectedCategories array to keep track of selected categories.
* Checks to see if the selected category matches the dice configuration,
* and calculates the score. If it does not match, assigns the score of 0.
* Post-condition: Shows the score category and total score in the scorecard.
*/
private void calculateCategoryScore(int playerNumber) {
selectedCategories[playerNumber][category] = 1;
int totalScore;
if(checkCategory(dieResults, category) == true) {
setCategoryScore(playerNumber, category);
int score = categoryScores[playerNumber][category];
display.updateScorecard(category, playerNumber, score);
calculateTotalScores(playerNumber);
totalScore = categoryScores[playerNumber][TOTAL];
display.updateScorecard(TOTAL, playerNumber, totalScore);
}
else {
categoryScores[playerNumber][category] = 0;
display.updateScorecard(category, playerNumber, 0);
calculateTotalScores(playerNumber);
totalScore = categoryScores[playerNumber][TOTAL];
display.updateScorecard(TOTAL, playerNumber, totalScore);
}
}
/*sets the score in the categoryScores matrix for each player
based on the scoring category they chose after rolling the dice*/
private void setCategoryScore(int playerNumber, int category) {
int score = 0;
if(category >= ONES && category <= SIXES) {
for(int i = 0; i < N_DICE; i++) {
if(dieResults[i] == category) {
score += category;
}
}
}
else if(category == THREE_OF_A_KIND || category == FOUR_OF_A_KIND || category == CHANCE) {
for(int i = 0; i<N_DICE; i++) {
score += dieResults[i];
}
}
else if(category == FULL_HOUSE) {
score = 25;
}
else if(category == SMALL_STRAIGHT) {
score = 30;
}
else if(category == LARGE_STRAIGHT) {
score = 40;
}
else if(category == YAHTZEE) {
score = 50;
}
categoryScores[playerNumber][category] = score;
}
/*sets the total scores for each player */
private void calculateTotalScores(int playerNumber) {
int upperScore = 0;
int lowerScore = 0;
int totalScore = 0;
for(int i = ONES; i <= SIXES; i++) {
upperScore += categoryScores[playerNumber][i];
}
for(int i = THREE_OF_A_KIND; i <= CHANCE; i++) {
lowerScore += categoryScores[playerNumber][i];
}
totalScore = upperScore + lowerScore;
categoryScores[playerNumber][UPPER_SCORE] = upperScore;
categoryScores[playerNumber][LOWER_SCORE] = lowerScore;
categoryScores[playerNumber][TOTAL] = totalScore;
}
/* Pre-condition: All players have completed the game.
* Calculates and displays the Upper Score, Upper Bonus, and LowerScore */
private void calculateResults() {
for(int i = 1; i <= nPlayers; i++) {
display.updateScorecard(UPPER_SCORE, i, categoryScores[i][UPPER_SCORE]);
display.updateScorecard(LOWER_SCORE, i, categoryScores[i][LOWER_SCORE]);
if(categoryScores[i][UPPER_SCORE] >= 63) {
categoryScores[i][UPPER_BONUS] = 35;
}
display.updateScorecard(UPPER_BONUS, i, categoryScores[i][UPPER_BONUS]);
categoryScores[i][TOTAL] = categoryScores[i][TOTAL] + categoryScores[i][UPPER_BONUS];
display.updateScorecard(TOTAL, i, categoryScores[i][TOTAL]);
}
}
/* Pre-condition: The game has ended, and all the final scores have been added up.
* Calculates which player has the highest score and what the highest score is
* and prints that information in a message at the very end of the game.*/
private void calculateWinner() {
int winningScore = 0;
int winningPlayerNumber = 0;
for(int i = 1; i<=nPlayers; i++) {
int x = categoryScores[i][TOTAL];
if( x > winningScore) {
winningScore = x;
winningPlayerNumber = i - 1;
}
}
display.printMessage("Congratulations, " + playerNames[winningPlayerNumber] + ", you're the winner with a total score of " + winningScore + "!");
}
/* Pre-condition: The player has finished rolling the dice and selects a category.
* This method returns true if the selected category matches
* to the actual category correctly, and false if it does not match. */
private boolean checkCategory(int[] dice, int category) {
boolean categoryMatch = false;
if(category >= ONES && category <= SIXES || category == CHANCE) {
categoryMatch = true;
}
else {
//creates an array for each possible dice value (1-6)
ArrayList <Integer> ones = new ArrayList<Integer>();
ArrayList <Integer> twos = new ArrayList<Integer>();
ArrayList <Integer> threes = new ArrayList<Integer>();
ArrayList <Integer> fours = new ArrayList<Integer>();
ArrayList <Integer> fives = new ArrayList<Integer>();
ArrayList <Integer> sixes = new ArrayList<Integer>();
/*goes through each rolled die and puts 1 as a place-holder into the appropriate ArrayList
* e.g. if the first die value is 1, then 1 is added to the ones ArrayList or
* if the second die value is 5, then 1 is added to the fives ArrayList*/
for(int i = 0; i < N_DICE; i++) {
if(dice[i] == 1) {
ones.add(1);
}
else if(dice[i] == 2) {
twos.add(1);
}
else if(dice[i] == 3) {
threes.add(1);
}
else if(dice[i] == 4) {
fours.add(1);
}
else if(dice[i] == 5) {
fives.add(1);
}
else if(dice[i] == 6) {
sixes.add(1);
}
}
if(category == THREE_OF_A_KIND) {
if(ones.size() >= 3 || twos.size() >= 3 || threes.size() >= 3 || fours.size() >= 3 || fives.size() >= 3 || sixes.size() >= 3) {
categoryMatch = true;
}
}
else if(category == FOUR_OF_A_KIND) {
if(ones.size() >= 4 || twos.size() >= 4 || threes.size() >= 4 || fours.size() >= 4 || fives.size() >= 4 || sixes.size() >= 4) {
categoryMatch = true;
}
}
else if(category == YAHTZEE) {
if(ones.size() == 5 || twos.size() == 5 || threes.size() == 5 || fours.size() == 5 || fives.size() == 5 || sixes.size() == 5) {
categoryMatch = true;
}
}
else if(category == FULL_HOUSE) {
if(ones.size() == 3 || twos.size() == 3 || threes.size() == 3 || fours.size() == 3 || fives.size() == 3 || sixes.size() == 3) {
if(ones.size() == 2 || twos.size() == 2 || threes.size() == 2 || fours.size() == 2 || fives.size() == 2 || sixes.size() == 2) {
categoryMatch = true;
}
}
}
else if(category == LARGE_STRAIGHT) {
if(ones.size() == 1 && twos.size() == 1 && threes.size() == 1 && fours.size() == 1 && fives.size() == 1){
categoryMatch = true;
}
else if(twos.size() == 1 && threes.size() == 1 && fours.size() == 1 && fives.size() == 1 && sixes.size() == 1) {
categoryMatch = true;
}
}
else if(category == SMALL_STRAIGHT) {
if(ones.size() >= 1 && twos.size() >= 1 && threes.size() >= 1 && fours.size() >= 1) {
categoryMatch = true;
}
else if(twos.size() >= 1 && threes.size() >= 1 && fours.size() >= 1 && fives.size() >= 1) {
categoryMatch = true;
}
else if(threes.size() >= 1 && fours.size() >= 1 && fives.size() >= 1 && sixes.size() >= 1) {
categoryMatch = true;
}
}
}
return categoryMatch;
}
}