Craps Statistics Analysis - Find Average Length of a craps game.

CrapsStatsAnalysis.java

/*
 * Name: Tony Silvestri
 * Date: 11/4/2019
 * Course Number: CSC-111
 * Course Name: Intro to Java
 * Problem Number: N/A
 * Email: silvestri@stcc.edu
 * Description:  Craps Statistics Analysis - Find average length of a craps game
 */

import java.util.Scanner;

public class CrapsStatsAnalysis {
	private final static String TITLE = "Craps Statistics Analysis";
	private final static String CONTINUE_PROMPT = "Do this again? [y/N] ";

	// **********************************************
	// Put as many methods you need here

	// roll dice, calculate sum and display results
	private static int rollDice() {
		// pick random die values
		int die1 = 1 + (int) (6 * Math.random());  // 1,2,3,4,5,6
		int die2 = 1 + (int) (6 * Math.random()); 
		return die1 + die2; // sum die values
	}

	private static int playCraps() {
	    final int LOST = 0, WON = 1, CONTINUE = 2;
	    int countRolls = 0;
		int gameStatus;
		int myPoint = 0;
		
		int sumOfDice = rollDice();
		countRolls++;
		switch (sumOfDice) {
		// win on first roll
		case 7:
		case 11:
			gameStatus = WON;
			break;

		// lose on first roll
		case 2:
		case 3:
		case 12:
			gameStatus = LOST;
			break;

		default:
			gameStatus = CONTINUE;
			myPoint = sumOfDice;
			break;
		}
		
		while (gameStatus == CONTINUE) {
			sumOfDice = rollDice();
			countRolls++;
			if (sumOfDice == myPoint) // win by making point
				gameStatus = WON;
			else if (sumOfDice == 7) // lose by rolling 7
				gameStatus = LOST;
		}

		return gameStatus == WON ? countRolls : -countRolls;
	}

	private static void generateStats(int numberOfGames, int catchAll) {
		int gameCounts[] = new int[catchAll + 1];
		int wonCount = 0;
		for (int i = 0; i < numberOfGames; i++) {
			int countRoll = playCraps();
			if (countRoll >= 0)
				wonCount++;
			else
				countRoll = -countRoll;
			if (countRoll >= catchAll)
				gameCounts[catchAll]++;
			else
				gameCounts[countRoll]++;
		}
		reportOnAnalysis(gameCounts, numberOfGames, wonCount);		
	}
	
	private static void reportOnAnalysis(int[] gameCounts, int numberOfGames, int gamesWon) {
		double average = (double) gamesWon / (double) numberOfGames * 100.0;
		System.out.printf("\nPercentage of Wins: %.4f\n", average);

		System.out.println("\nNumber of Rolls Needed to Finish Game");
		for (int i = 1; i < gameCounts.length - 1; i++)
			System.out.printf("%4d: %,8d\n", i, gameCounts[i]);
		System.out.printf("%3d+: %,8d\n", gameCounts.length - 1, gameCounts[gameCounts.length - 1]);
		
		int sum = 0;
		for (int i = 1; i < gameCounts.length; i++)
			sum += i * gameCounts[i];
		average = (double)sum / (double) numberOfGames;
		System.out.printf("\nAverage Length of Game: %.4f rolls.\n\n", average);
	}

	// **********************************************
	// Start your logic coding in the process method
	private static void process(Scanner sc, String args[]) {
		System.out.print("Enter number of games: ");
		int games = sc.nextInt();
		System.out.print("Enter top end catch all value: ");
		int catchAll = sc.nextInt();
		sc.nextLine();  //Very Important
		generateStats(games, catchAll);
	}

	// **********************************************
	// Do not change the doThisAgain method
	private static boolean doThisAgain(Scanner sc, String prompt) {
		System.out.print(prompt);
		String doOver = sc.nextLine();
		return doOver.trim().equalsIgnoreCase("Y");
	}

	// **********************************************
	// Do not change the main method
	public static void main(String args[]) {
		System.out.println("Welcome to " + TITLE);
		Scanner sc = new Scanner(System.in);
		do {
			process(sc, args);
		} while (doThisAgain(sc, CONTINUE_PROMPT));
		sc.close();
		System.out.println("Thank you for using " + TITLE);
	}

}