Answer to Monday's Grinch Question

The programming question this week was to decode a hidden message within the text of a Christmas quote from Dr Suess' How The Grinch Stole Christmas.

The cipher code:

5-7-1-3 8-7-1-3 7-3 3-3 5-9-1-2 4-5-0-3 1-4 2-2-1-2 2-4-0-6 4-6 4-2-1-2 1-13 4-4-0-7

when applied to the quotation becomes:

is it Christmas without a box with a ribbon or a puzzling package

Here's my version of the program:

import java.util.Scanner;
public class BookCipher {

  public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    System.out.println("Enter in the code text: ");
    String bookText = input.nextLine();

    //it makes life easier to remove the spaces
    //between sentences
    bookText = bookText.replace(". ", ".");
    bookText = bookText.replace("? ", "?");

    //split the code text into sentences using
    //a regex expression. It says split on any
    //quesion mark or fullstop
    String[] sentences = bookText.split("[\\?\\.]");

    System.out.println("Enter in text cipher:");
    String cipher = input.nextLine();
    String[] ciphers = cipher.split(" ");
    StringBuilder hiddenSentence = new StringBuilder();
    for (String s:ciphers)
    {
      String[] positions = s.split("-");

      //find right sentence
      String sentence = sentences[Integer.parseInt(positions[0])-1];

      //get rid of any commas from sentence
      sentence = sentence.replace(",", "");

      String[] words = sentence.split(" ");

      //find the right word
      String word = words[Integer.parseInt(positions[1])-1];

      //if there is a substring defined in the cipher
      //then find the word within a word
      if (positions.length == 4)
      {
        String subWord = word.substring(Integer.parseInt(positions[2]), Integer.parseInt(positions[3]));
        hiddenSentence.append(subWord + " ");
      }
      else
      {
        hiddenSentence.append(word + " ");
      }
    }
    System.out.println(hiddenSentence);
  }
}