Question

Java

Craps in Java. The following are the rules for a pass bet in the game of craps. Roll two six-sided dice, and let x be their sum. If x is 7 or 11, you win. If x is 2, 3, or 12, you lose. Otherwise, repeatedly roll two the dice until their sum is either x or 7. If their sum is x, you win. If their sum is 7, you lose. Compose a modular program to estimate the probability of winning a pass bet. Modify your program to handle loaded dice, where the probability of a die landing on 1 is taken from the command line, the probability of landing on 6 is 1/6 minus that probability, and 2-5 are assumed equally likely.

Answer 1

Below is the solution:

Craps.java:

import java.util.Random;
import java.util.Scanner;
//import java.lang.String;

public class Craps {
   private final static Random random = new Random(); // Random class
   // main method

   public static void main(String[] args) {
       Scanner keyboard = new Scanner(System.in); // scanner object
       String answer;
       int r1, r2;
       int winScore = 0, trials = 0;
       do {
           r1 = random.nextInt(6) + 1; // store roll1 in a new r1 variable
           r2 = random.nextInt(6) + 1; // store roll2 in a new r2 variable
           // sum of the two rolls
           int thePoint = (r1 + r2); // add the two dice roll
           // ptints the sum of two dice
           System.out.print("You rolled " + thePoint + " . ");
           // check for the win point of sum dice
           if (thePoint == 7 || thePoint == 11) { // if sum of two roll dice is 7 or 11
               System.out.println("You Win!"); // winner
               winScore++; // win times add
               trials++; // try times add
               // cehck for the loose dice score of sum
           } else if (thePoint == 2 || thePoint == 3 || thePoint == 12) { // if sum of two roll dice is 2 or 3 or 12
               System.out.println("You Lose!"); // loser
               trials++; // try times add
           } else { // otherwise
               while (thePoint != 7) { // loop run untill the sum of two dice roll is 7
                   r1 = random.nextInt(6) + 1; // store roll1 in a new r1 variable
                   r2 = random.nextInt(6) + 1; // store roll2 in a new r2 variable
                   int roll2 = (r1 + r2); // add the two dice roll

                   if (thePoint == roll2) {
                       System.out.println("You Win!");
                       winScore++; // win times add
                       trials++; // try times add
                       break;
                   } else if (roll2 == 7) {
                       System.out.println("You Lose!");
                       trials++; // try times add
                   }
               }
           }
           System.out.println("Would you like to play again? [y/n]"); // ask to play again(y/n)
           answer = keyboard.nextLine().toLowerCase(); // accept the letter to play or not
       } while (answer.equals("y"));

       System.out.println("Winning percentage = " + 1.0 * winScore / trials); // prints the winning score
   }
}

output:

You rolled 9 . You Lose!
You Lose!
You Lose!
You Lose!
You Win!
Would you like to play again? [y/n]
y
You rolled 9 . You Lose!
You Lose!
You Win!
Would you like to play again? [y/n]
y
You rolled 7 . You Win!
Would you like to play again? [y/n]
y
You rolled 7 . You Win!
Would you like to play again? [y/n]
y
You rolled 4 . You Win!
Would you like to play again? [y/n]
y
You rolled 11 . You Win!
Would you like to play again? [y/n]
y
You rolled 8 . You Win!
Would you like to play again? [y/n]
y
You rolled 12 . You Lose!
Would you like to play again? [y/n]
y
You rolled 4 . You Win!
Would you like to play again? [y/n]
y
You rolled 7 . You Win!
Would you like to play again? [y/n]
y
You rolled 6 . You Win!
Would you like to play again? [y/n]
n
Winning percentage = 0.5882352941176471