CSCI 121 Programming Assignment 3

CryptoQuip!

Create a GUI application that implements the popular Cryptoquip program that appears on the comic page of newspapers. Here is a possible layout (feel free to develop a better one):

Figure 1: The initial puzzle

The text areas labeled “Puzzle” and “Solution” initially contain the same text—the encoded quip. As the user makes substitutions for letters in the encoded puzzle, the text area labeled “Solution” will change to reflect the substitutions.

In this screen shot you will notice 2 rows of letters. Using the mouse, the user can select a letter from the upper row and a letter from the lower row. The selected letters are highlighted. When the user presses the “Substitute” button, each of occurrence of the upper letter in the puzzle will be replaced by the lower letter. The following shots illustrate this feature:

Figure 2: The user wants to replace T’s with Y’s

Figure 3: After the user presses the “Substitute” key

You may optionally supply a “Hint” feature that allows the user to request a hint when he gets stuck. You may use a JOptionPane dialog for this if you wish:

Figure 4: User requested a hint

The puzzle solver continues to make letter substitutions until she reaches the solution. In the following figure, the user is getting ready to make the final substitution (G = C) that solves the puzzle:

Figure 5: Solution is near!

When the puzzle is solved, the program should display a congratulatory message:

Figure 6: Success!

You may also optionally allow the user to load a new puzzle from a text file on disk. Use a JFileChooser to show an Open dialog and encode the text file as you did the opening puzzle.

Figure 7: User chooses text file crypto1 for new puzzle.

The following figure shows the newly-encoded puzzle. Note that the encoding is not the same as that in the previous puzzle:

Figure 8: The new puzzle after loading from the disk file.

Call your application CryptoQuip.java.

Suggestions

• You need a way to create a “random” encryption scheme. You must ensure that no letter substitutes for itself. You may take the following approach:
  
  String alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
  String temp = alphabet;
  String code = "";
  int index = 0;
  while there are more letters
  generate an integer n, where 0 £ n < temp.length
  if temp.charAt(n) is not the same as alphabet.charAt(index)
  concatenate temp.charAt(n) to code
  increment index
  remove the character at position n from temp
  
  Note that the last step causes the length of temp to decrease by 1. When the algorithm is finished, code will contain the encoding string. For example, it may be that code = "XMEZHGFCSRTOBULYWIJNKDQAPV". Thus, we have the substitutions X = A, M = B, …, V = Z. Use the encoding string to encode the puzzle text.

• I used arrays of JLabels and a mouse listener to implement the rows of letters. You may use any scheme you like, so long as it is easy and intuitive to use as well as “idiot-proof”.

• I used JTextAreas to display the puzzle and solution strings. This allows the text to occupy more that one line. Be sure to enable line wrap (setLineWrap(true)) and break text at word boundaries (setWrapStyleWord(true)).

• The hint and new puzzle features are optional. If you implement them correctly, you can earn a few bonus points.

• This program is due on Monday of the last week of class. Because of time constraints for grading this assignment, NO LATE ASSIGNMENTS WILL BE ACCEPTED. I will not require a paper copy for this assignment. To submit your program, email your java file(s) to mclark@wvutech.edu. Your email must be submitted by 3:00 pm at the latest.