Java Game: Test Your Country Knowledge with Trees

import TreePackage.*; import java.util.Scanner; public class GuessingGame { public static void main ( String [] args ) { String response ; DecisionTree < String > gameTree = new DecisionTree <>( "Is it in North America?" , "Brazil" , "U.S.A." ); do { System . out . println ( "Think of a country and I will guess it. " ); gameTree = play (gameTree); System . out . print ( "Play again? " ); response = getUserResponse (); } while ( response . toLowerCase (). equals ( "yes" )); System . out . println ( "Bye!" ); } // end main public static String getUserResponse () { Scanner stdin = new Scanner ( System . in ); return stdin . nextLine (); } // end getUserResponse public static boolean isUserResponseYes () { String answer = getUserResponse (); if ( answer . toLowerCase (). equals ( "yes" )) return true ; else return false ; } // end isUserResponseYes public static DecisionTree < String > play ( DecisionTree < String > gameTree ) { // Initialize current node to root gameTree . resetCurrentNode (); while (! gameTree . isAnswer ()) { // Ask current question System . out . println ( gameTree . getCurrentData ()); if ( isUserResponseYes ()) gameTree . advanceToYes (); else gameTree . advanceToNo (); } // end while assert gameTree . isAnswer (); // Assertion: Leaf is reached // Make guess System . out . println ( "My guess is " + gameTree . getCurrentData () + ". Am I right?" ); if ( isUserResponseYes ())

System . out . println ( "I win." ); else learn (gameTree); return gameTree; } // end play // Responds to the user when this program makes a wrong guess and // extends the decision tree so that this guess is not made again. public static void learn ( DecisionTree < String > gameTree ) { System . out . println ( "I give up; what are you thinking of? " ); //TODO set correct answer string //TODO set current answer string String correctAnswer = getUserResponse (); String currentAnswer = gameTree . getCurrentData (); System . out . println ( "Give me a question whose answer is yes for " + correctAnswer + " but no for " + currentAnswer); String newQuestion = getUserResponse (); // TODO create a new question with current data // TODO set responses based on current answer and correct answer gameTree . setCurrentData (newQuestion); gameTree . setResponses (currentAnswer, correctAnswer); } // end learn } // end GuessingGame /* Sample output: Think of a country and I will guess it. Is it in North America? yes My guess is U.S.A.. Am I right? yes I win. Play again? yes Think of a country and I will guess it. Is it in North America? no My guess is Brazil. Am I right? no I give up; what are you thinking of? England Give me a question whose answer is yes for England but no for Brazil Is it in Europe? Play again? yes Think of a country and I will guess it. Is it in North America? no Is it in Europe? yes My guess is England. Am I right? yes

I win. Play again? no Bye! */