/**
 * Play the game of 24, where you are given 4 numbers and you must apply the
 * basic mathematical operators (+, -, *, /) to the four numbers (using each
 * number exactly once) to yield the value 24.
 *      
 * Class: CS 102, Spring 2009
 * Lab: Billie Joe Armstrong, Wed. 6:00 AM
 * System: BlueJ 2.1.1, jsdk 1.5, Windows XP
 *
 * @author  Dale Reed
 * @version January 13, 2009
 * 
 * Running the program looks like (where what the user thinks of is shown in parenthesis, but doesn't apear on screen:


 */

// Import libraries needed by the program
import java.util.Scanner;         // used for console input
 
// Declare the class
public class TwentyFourB
{
    // Fields that can be accessed anywhere in the class go here
    Scanner keyboard = new Scanner( System.in);     // used to read user input
  
    //----------------------------------------------------------------------------------------
    // main() - startup main loop.  It is necessary to create an instance of this class
    //          and then call a method from that instance, otherwise there are all kinds
    //          of error messages having to do with non-static objects (e.g. keyboard)
    //          being called from a static context (e.g. main).  By creating the instance
    //          and *then* using keyboard, it is not longer being called from a static
    //          context.  Don't worry about understanding all this right now.
    public static void main(String[] args)  
    {
        // create an instance of this class
        TwentyFourB theTwentyFourBInstance = new TwentyFourB();
        // call a non-static method to do everything else
        theTwentyFourBInstance.mainLoop();     
    }
        
    
    //----------------------------------------------------------------------------------------
    // mainLoop() - display identifying information and run main loop.
    //      In your program, you will only add code inside this method.  You don't need to
    //      change anything above except for the comments at the top of the program.
    //
    void mainLoop()  
    {        
        // Display identifying information
        System.out.println( "Author: Dale Reed \n" +
                            "Program: #1, TwentyFour \n" +
                            "TA: Englebert Humberdink, T 4-5 \n"+
                            "Jan 13, 2009");
        System.out.println();
                 
        //Display game instructions and pause display
        System.out.println( "Welcome to the game of TwentyFour.  Choose one of the sets of 4 numbers below .\n" +
                            "You then need to use each of those four numbers exactly once, combining them somehow \n" +
                            "with the basic mathematical operators (+,-,*,/) to yield the value twenty-four. \n" +
                            "Possible sets of 4 numbers are: \n" +
                            "   8         5         7         5          9         8      \n" +
                            " 5   1     1   1     8   8     9   4      2   2     6   4    \n" +
                            "   8         6         2         3          5         2      \n" +
                            " \n");
                            
        // declare variables
        String operator = "";                      // stores user input
        int number = 0;
        int answer = 0;

        // Prompt for and read in the 4 numbers to be used
        System.out.print("Please enter the first number: ");
        answer = keyboard.nextInt();
                              
        int loopCounter = 1;            // value counts from 1..3, representing the 3 pairs of numbers to be used.
        // execute the loop 3 times, since there are 3 operators to be applied
        while( loopCounter <4) {
            // find out which operator is to be used
            System.out.print( "Enter the operator to be used (+,-,*, or /): ");             
            operator = keyboard.next();     // read user input
            
            System.out.print( "Enter the next number: ");
            number = keyboard.nextInt();        // read the next number
            
            // apply the operator to the two values: answer  and  nextNumber
            if( operator.equals("+") ) {
                answer = answer + number;
            }
            else if( operator.equals("-") ) {
                answer = answer - number;
            }  
            else if( operator.equals("*") ) {
                answer = answer * number;
            }
            else if( operator.equals("/") ) {
                answer = answer / number;
            }
            
            // display the answer
            System.out.println("That gives: " + answer );
            System.out.println();
            
            // increment loop counter
            loopCounter = loopCounter + 1;    
        }//end while( loopCounter...
            
        // Leave a blank line before the answer
        System.out.println();
        
        // Now check the answer
        if( answer == 24) {
             // answer was correct
             System.out.println("Well done, genius! \n");  
        }
        else {
             // Answer was not correct
             System.out.println("Better luck next time. \n");
        }
        
        System.out.println("Goodbye, thanks for playing. \n");
  
    }//end mainLoop()
    
}//end class MagicNumber