Reddit Daily Programmer #380

Main.java

// https://www.reddit.com/r/dailyprogrammer/comments/cmd1hb/20190805_challenge_380_easy_smooshed_morse_code_1/
import java.io.IOException;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.*;

public class Main {

  private static final String[] morseAlphabet = ".- -... -.-. -.. . ..-. --. .... .. .--- -.- .-.. -- -. --- .--. --.- .-. ... - ..- ...- .-- -..- -.-- --..".split(" ");
  private static final String alphabet = "abcdefghijklmnopqrstuvwxyz";

  public static String parseWord(String word) {
    StringBuilder morseString = new StringBuilder();
    for (char ch : word.toCharArray()) {
      int index = alphabet.indexOf(ch);
      morseString.append(morseAlphabet[index]);
    }
    return morseString.toString();
  }

  private static List<String> readWordlist() throws IOException {
    List<String> words = new ArrayList<>();
    Path wordsFile = Paths.get("./src/wordlist.txt");
    Scanner scanner = new Scanner(wordsFile);
    while (scanner.hasNextLine()) {
      words.add(scanner.nextLine());
    }
    return words;
  }

  public static void main(String[] args) {
    List<String> wordList = null;
    try {
      wordList = readWordlist();
    } catch (IOException e) {
      e.printStackTrace();
    }

    System.out.println("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
    System.out.println("Find the only sequence that's the code for 13 different words.");
    Map<String, List<String>> wordMap = new HashMap<>();
    for (String word : wordList) {
      String morseWord = parseWord(word);
      if (wordMap.containsKey(morseWord)) {
        List<String> words = new ArrayList<>(wordMap.get(morseWord));
        words.add(word);
        wordMap.put(morseWord, words);
      } else {
        wordMap.put(morseWord, Arrays.asList(new String[]{word}));
      }
    }

    for (Map.Entry<String, List<String>> entry : wordMap.entrySet()) {
      if (entry.getValue().size() == 13) {
        System.out.println(entry.getKey());
      }
    }

    System.out.println("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
    System.out.println("Find the only word that has 15 dashes in a row");
    for (String word : wordList) {
      String morseWord = parseWord(word);
      int counter = 0;
      int longest = 0;
      for (char c : morseWord.toCharArray()) {
        if (c == '-') {
          counter++;
          if (counter > longest)
            longest = counter;
        } else {
          counter = 0;
        }
      }
      if (longest == 15) {
        System.out.println(word);
        System.out.println(morseWord);
      }
    }

    System.out.println("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
    System.out.println("Find 21-letter words that are perfectly balanced");
    for (String word : wordList) {
      if (word.length() == 21) {
        String morseWord = parseWord(word);
        int dots = 0;
        int dashes = 0;
        for (char c : morseWord.toCharArray()) {
          switch (c) {
            case '.':
              dots++;
              break;
            case '-':
              dashes++;
              break;
          }
        }
        if (dots == dashes) {
          System.out.println(word);
        }
      }
    }

    System.out.println("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
    System.out.println("Find the only 13-letter word that encodes to a palindrome");
    for (String word : wordList) {
      if (word.length() == 13) {
        String morseWord = parseWord(word);
        String reversed = new StringBuilder(morseWord).reverse().toString();
        if (morseWord.equals(reversed)) {
          System.out.println(word);
          System.out.println(morseWord);
        }
      }
    }
    System.out.println("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
    System.out.println("Find the 13-character sequences that don't appear in the encoding of any word");
    int limit = (int) Math.pow(2, 13);
    for (int i = 0; i < limit; i++) {
      String binary = Integer.toBinaryString(i);
      StringBuilder builder = new StringBuilder();
      for (char c : binary.toCharArray()) {
        if (c == '0') {
          builder.append('.');
        } else if (c == '1') {
          builder.append('-');
        }
      }
      int length = Integer.toBinaryString(i).length();
      if (length < 13) {
        for (int j = 0; j < (13 - length); j++) {
          builder.insert(0, '.');
        }
      }

      boolean contained = false;
      if (builder.length() == 13) {
        for (String key : wordMap.keySet()) {
          if (key.contains(builder)) {
            contained = true;
            break;
          }
        }
        if (!contained) {
          System.out.println(builder);
        }
      }
    }
  }
}