lab1/Activity2/GreaterLessGame.java

   1 /*
   2  * GreaterLessGame.java
   3  *
   4  * Version:
   5  *    $Id: GreaterLessGame.java,v 1.5 2008/03/13 18:51:11 rmh3093 Exp $
   6  *
   7  * Revisions:
   8  *    $Log: GreaterLessGame.java,v $
   9  *    Revision 1.5  2008/03/13 18:51:11  rmh3093
  10  *    Fix run time issues
  11  *
  12  *    Revision 1.4  2008/03/13 18:38:10  rmh3093
  13  *    fix compile issues
  14  *
  15  *    Revision 1.3  2002/12/04 17:01:28  cs2
  16  *    Corrected typo -- ptt
  17  *
  18  */
  19
  20 import java.io.BufferedReader;
  21 import java.io.InputStreamReader;
  22 import java.io.IOException;
  23 import java.util.Random;
  24
  25 /**
  26  * Play the game of "Greater than, less than".  The computer will think of
  27  * a random number from 0 to 100 and you try to guess it.  The computer
  28  * will give you clues by telling you whether your guess is greater or
  29  * less than the number it is thinking of.  You have 25 tries to guess
  30  * the number.
  31  *
  32  * This program contains errors!!
  33  *
  34  * @author Aleksey Tentler
  35  */
  36
  37 public class GreaterLessGame {
  38
  39     // The maximum number the computer will guess
  40     private static final int MAX_GUESS = 100;
  41
  42     // The number of guesses a user can make
  43     private static final int NUMBER_OF_TRIES = 25;
  44
  45     // Set this constant to true to see the secret number
  46     private static final boolean SHOW_SECRET_NUMBER = false;
  47
  48     /**
  49      * This method plays the game, keeping track of how many tries are used.
  50      *
  51      * @param secret the number the computer is thinking of.
  52      */
  53     private static void playTheGame( int secret ) {
  54         int tries = 0;            // Number of tries
  55         boolean correct = false;   // Did the user guess the number
  56
  57         // Give the user 25 tries to guess the number
  58         while ( !correct && tries <= NUMBER_OF_TRIES ) {
  59             // Calls isGuessCorrect to check whether the guess is correct
  60             // Obtains the user's guess by calling getGuess
  61             // You can assume that the getGuess function works correctly
  62             // isGuessCorrect, however, may have errors
  63             correct = isGuessCorrect( getGuess(), secret );
  64             tries++;
  65         }
  66
  67         // Check whether the user won or lost
  68         if( correct ) {
  69             System.out.println( "\nYou got it! The answer is " + secret );
  70             System.out.println( "\nYou did it in " + tries + " tries." );
  71         }
  72         else {
  73             System.out.println( "\nYou took too long. You lose!");
  74         }
  75     }
  76
  77     /**
  78      * Checks whether the guess is correct and prints whether the number
  79      * is smaller or greater than the guess.
  80      *
  81      * @param secret the computer's secret number.
  82      * @param guess the user's guess.
  83      *
  84      * @return true if the guess is correct, false otherwise.
  85      */
  86     private static boolean isGuessCorrect( int guess, int secret ) {
  87         boolean retVal = (secret == guess);  // Value to return
  88
  89         if( secret < guess ) {
  90             System.out.println( "The number is less than " + guess );
  91         }
  92         else {
  93             System.out.println( "The number is more than " + guess );
  94         }
  95
  96         return retVal;
  97     }
  98
  99     // --------------------------------------
 100     // EVERYTHING BELOW THIS LINE IS CORRECT!
 101     // --------------------------------------
 102
 103     private static BufferedReader in = null;  // Source of input
 104
 105     /**
 106      * Play the game.
 107      *
 108      * @param args seed for random number geneator.
 109      */
 110
 111     public static void main( String args[] ) {
 112         Random rand = new Random();  // Source of random numbers
 113
 114         // See if a seed was specified on the command line
 115         if ( args.length == 1 ) {
 116             try {
 117                 rand.setSeed( Long.parseLong( args[ 0 ] ) );
 118             }
 119             catch ( NumberFormatException e ) {
 120                 System.err.println( "Invalid seed" );
 121                 System.exit( 1 );
 122             }
 123         }
 124
 125         // Connect streams to standard input
 126         in = new BufferedReader( new InputStreamReader( System.in ) );
 127
 128         // Guess a secret number.  Note that nextInt() returns an
 129         // an integer between 0 and N-1 which is why we must use
 130         // MAX_GUESS+1
 131         int secret = rand.nextInt( MAX_GUESS + 1 );
 132
 133         // Debugging help
 134         if( SHOW_SECRET_NUMBER ) {
 135             System.out.println( "\n[ The secret number is " + secret + "]\n" );
 136         }
 137
 138         // Play the game
 139         playTheGame( secret );
 140     }
 141
 142     /**
 143      * Read the next valid number from the input stream.
 144      *
 145      * @return the next valid integer in the input stream.
 146      */
 147     private static int getGuess() {
 148         int guess = -1;  // The number that was entered
 149
 150         // Read until a valid number is entered
 151         do {
 152             System.out.print( "Enter a number between 0 and 100:  " );
 153
 154             try {
 155                 guess = Integer.parseInt( in.readLine() );
 156
 157                 if ( guess < 0 || guess > MAX_GUESS ) {
 158                     System.out.println( "Number out of range." );
 159                     guess = -1;
 160                 }
 161             }
 162             catch( NumberFormatException e ) {
 163                 System.out.println( "Not an integer." );
 164             } catch( IOException e ) {
 165                 System.out.println( "Bad Input!\n" );
 166             }
 167
 168         } while( guess < 0 );
 169
 170         return guess;
 171     }
 172
 173 } // GreaterLessGame