[2015-10-28] Challenge #238 [Intermediate] Fallout Hacking Game : dailyprogrammer

[2015-10-28] Challenge #238 [Intermediate] Fallout Hacking Game : dailyprogrammer
The popular video games Fallout 3 and Fallout: New Vegas have a computer "hacking" minigame where the player must correctly guess the correct password from a list of same-length words. Your challenge is to implement this game yourself.
The game operates similarly to the classic board game Mastermind. The player has only 4 guesses and on each incorrect guess the computer will indicate how many letter positions are correct.
For example, if the password is MIND and the player guesses MEND, the game will indicate that 3 out of 4 positions are correct (M_ND). If the password is COMPUTE and the player guesses PLAYFUL, the game will report 0/7. While some of the letters match, they're in the wrong position.
Ask the player for a difficulty (very easy, easy, average, hard, very hard), then present the player with 5 to 15 words of the same length. The length can be 4 to 15 letters. More words and letters make for a harder puzzle. The player then has 4 guesses, and on each incorrect guess indicate the number of correct positions.
Here's an example game:

Difficulty (1-5)? 3  SCORPION  FLOGGING  CROPPERS  MIGRAINE  FOOTNOTE  REFINERY  VAULTING  VICARAGE  PROTRACT  DESCENTS  Guess (4 left)? migraine  0/8 correct  Guess (3 left)? protract  2/8 correct  Guess (2 left)? croppers  8/8 correct  You win!  

You can draw words from our favorite dictionary file: enable1.txt. Your program should completely ignore case when making the position checks.
There may be ways to increase the difficulty of the game, perhaps even making it impossible to guarantee a solution, based on your particular selection of words. For example, your program could supply words that have little letter position overlap so that guesses reveal as little information to the player as possible.

    public static void main(String[] args) throws Exception {
        List<String> wordList = Files.readAllLines(Paths.get("enable1.txt"), StandardCharsets.UTF_8);
        Scanner sc = new Scanner(System.in);
        Random rng = new Random();
        System.out.print("Difficulty? (1-5) ");
        int d = sc.nextInt();
        int len = d*2+2;
        List<String> words = new ArrayList<>();

        // Generate and display words
        for (int i = 0; i < d*2+3; i++) {
            int n;
            String w;
            do {
                n = rng.nextInt(wordList.size());
                w = wordList.get(n);
            } while (w.length() != len);
            wordList.remove(n);
            System.out.println(w.toUpperCase());
            words.add(w);
        }

        // Game
        String pass = words.get(rng.nextInt(words.size()));
        for (int g = 4; g > 0; g--) {
            String guess;
            do {
                System.out.printf("Guess (%d left)? ", g);
                guess = sc.next();
                if (guess.length() != len)
                    System.out.printf("Guess must have length of %d.%n", len);
            } while (guess.length() != len);
            System.out.print(numCorrect(guess, pass));
            if (guess.equals(pass)) {
                System.out.print("You win!");
                System.exit(0);
            }
        }
        System.out.println("You lose. The password was " + pass + ".");
    }

    // Given two strings, returns the number of characters they have in common.
    public static String numCorrect(String g, String p) {
        int c = 0;
        for (int i = 0; i < g.length(); i++)
            if (g.charAt(i) == p.charAt(i))
                c++;
        return c + "/" + g.length() + " correct" + "\n";
    }


2.
    public static final Random rand = new Random();
    public static final int GUESSES = 4;

    public static void main(String[] args) throws IOException {
        try (Scanner scanner = new Scanner(System.in)) {
            List<String> lines = Util.getLinesFromFile(Util.WORDLIST);
            Collections.shuffle(lines);

            System.out.print("Choose a difficulty (0-4): ");
            int difficulty = getWordLengthFromDifficulty(scanner.nextInt());

            List<String> words = lines
                .stream()
                .filter(line -> line.length() == difficulty)
                //.sorted((s1, s2) -> Integer.compare(rand.nextInt(), rand.nextInt())) not transitive :(
                .collect(Collectors.toList())
                .subList(0, 10);

            String password = words.get(rand.nextInt(words.size()));
            System.out.println(String.join("\n", words));

            int length = password.length();
            for (int tries = 0; tries < GUESSES; ++tries) {
                System.out.print("Guess (%d left): ", GUESSES - tries);
                String guess = scanner.next().toLowerCase();

                long correct = guess(password, guess);
                if (correct == length) {
                    System.out.print("You win!");
                    return;
                }

                System.out.printf("%d/%d correct.\n", correct, length);
            }

            System.out.printf("You lose, the word was %s.", password);
        }
    }

    public static int getWordLengthFromDifficulty(int difficulty) {
        switch (difficulty) {
        case 0: return rand.nextInt(5 - 4) + 4;
        case 1: return rand.nextInt(8 - 6) + 6;
        case 2: return rand.nextInt(10 - 9) + 9;
        case 3: return rand.nextInt(12 - 11) + 11;
        case 4: return rand.nextInt(15 - 13) + 13;
        default: return -1;
        }
    }

    public static long guess(String password, String guess) {
        return IntStream.range(0, password.length()).filter(n -> password.charAt(n) == guess.charAt(n)).count();
    }

       
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