Craps.java

import java.util.Random;


/**
* Simulates the game of craps. A modified version of Owen Astrachan's
* program, A Computer Science Tapestry, 1997, McGraw-Hill, p. 225-231.
* Revised on 4/10/97, Cary Matsuoka.
* Converted to Java on 6/2/2002, George Peck.
* Modified 1/19/06 Jason Quesenberry and Nancy Quesenberry.
*
*/
public class Craps{

  private Random myDie;
  private int myGamesWon, myGamesToPlay;
  private double myPercentWon;

  /**
  * Constructor for the Craps object
  */
  public Craps(){
    myDie = new Random();
  }

  /**
  * Plays craps the specified number of times and evaluates
  * the number of games won and winning percentage
  *
  * @param gamesToPlay Number of trials (games)
  */
  public void playGame(int gamesToPlay){
    myGamesToPlay = gamesToPlay;
    myGamesWon = 0;
    for (int game = 0; game < myGamesToPlay; game++){
      if (winGame()){
        myGamesWon++;
      }
    }
    myPercentWon = (double) myGamesWon / myGamesToPlay * 100;
  }

  /**
  * Description of the Method
  *
  * @return Total number of games won
  */
  public int gamesWon(){
    return myGamesWon;
  }

  /**
  * Description of the Method
  *
  * @return Winning percentage
  */
  public double percentWon(){
    return myPercentWon;
  }

  /**
  * Gets the point attribute of the Craps object
  *
  * @param point Value to match, 2 <= point <= 12
  * @return true if point is matched, false if 7 is rolled first
  */
  private boolean getPoint(int point){// precondition: 2 <= point <= 12
  int sum;
  do{
    sum = rollDice();
  } while ((sum != point) && (sum != 7));// <--- application of DeMorgan's Laws
/*
        if (sum == point)
          System.out.println("point is matched, player won");
        else
          System.out.println("crapped out");
*/
    return (sum == point);
  }

  /**
  * Determines if a single game of craps is won or lost
  *
  * @return true if a single game of craps is won, otherwise false
  */
  private boolean winGame(){
    int point = rollDice();

    switch (point){
        case 7:
        case 11:
          // System.out.println("7 or 11 rolled, win");
          return true;
        case 2:
        case 3:
        case 12:
          // System.out.println("2, 3,or 12 rolled, lost");
          return false;
        default:
          return getPoint(point);
    }
  }

  /**
   * Simulates the rolling of two dice
   *
   * @return sum of rolling two dice
   */
  private int rollDice(){
    int first = myDie.nextInt(6) + 1;
    int second = myDie.nextInt(6) + 1;
    int sum = first + second;
    return sum;
  }

}