| Letter A-G | Code | Letter H-N | Code | Letter O-U | Code | Letter V-Z | Code |
|—|—|—|—|—|—|—|—|
| A | β’ β | H | β’ β’ β’ β’ | O | β β β | V | β’ β’ β’ βΒ |
| B | β β’ β’ β’ | I | β’ β’ | P | β’ β β β’ | W | β’ β β |
| C | β β’ β β’ | J | β’ β β β | Q | β β β’ β | X | β β’ β’ β |
| D | β β’ β’ | K | β β’ β | R | β’ β β’ | Y | β β’ β β |
| E | β’ | L | β’ β β’ β’ | S | β’ β’ β’ | Z | β β β’ β’ |
| F |β’ β’ β β’ | M | β β | T | β |
| G | β β β’ | N | β β’ | U | β’ β’ β |
> Morse code was invented by Samuel Morse in 1832. Letters and numbers are represented by a series of dots and dashes – a dash sound lasts three times longer than a dot sound.
## Morse Code Translator:
Morse code is a common code that is used to encode messages consisting of letters and digits (this project only handles letters). Each letter consists of a series of dots (using asterisks for ease of use here) and dashes; for example, the code for the letter ***a*** is `*-` and the code for the letter ***b*** is `-***`.
– Store each letter of the alphabet in a node of a binary tree of height 5. The root node is at level 1 and stores no letter. The left node at level 2 stores the letter ***e*** (code is `*`), and the right node stores letter ***t*** (code is `-`).Β The 4 nodes at level 3, from left-to-right, store the letters with codes (`**`, `*-`, `-*`, `–`).Β If your tree is visualized, it would look like:
– To build the tree above, read a text file in which **each line consists of a letter followed by its code** (i.e., `b -***`) and add the node appropriately to the tree using the morse code. The letters should be ordered by tree level, from left-to-right (i.e., e, t, i, a, n, m, etc. where each letter is on its own line with the code as described previously).
– To find the position to add for a letter in the tree, use the code and branch left for a dot
(`*`) and branch right for a dash (`-`).
– To decode the message using the `MorseCodeTree`, translate each letter using the tree (branch left for a dot, branch right for a dash). Make sure you use a space (` `) as a delimiter between coded letters (i.e., `**** * *-** *-** — *– — *-* *-** -**`Β translates to `helloworld`).
## Implementation Notes:
– You will need to complete the generic implementation of the `BinaryTree` data structure first (see slides). Once it is tested and complete, proceed to solve the problem above.
– Build the text file EXACTLY as specified above (if not, it becomes much more difficult and will break code that follows)
– Create a `MorseCodeTree` that extends `BinaryTree`, adding methods that specifically do the translation/reading described above. Starter code and documentation for translating Morse code has been provided for you.
– Note: Do not override `readBinaryTree()` method, as that works completely differently! Instead, create a `readMorseCodeTree()` method (it is simpler, doesn’t need to be recursive as you can see from the description above).
– JUnit tests that test every letter, A-Z, is translated from morse code using the tree correctly, as well as a few multi-letter tests (other tests besides `**** * *-** *-** — *– — *-* *-** -**`Β translating to `helloworld`, etc.) have been provided in `MorseCodeTreeTest`. Given this, consider how your `MorseCodeTree` methods deal with errors like invalid characters (characters other than * or -)?
– **Provide a driver menu program** that builds the `MorseCodeTree` and asks the user if they want to 1) test output for all morse code letters with their respective translated alphabet letters (make sure you are using the `MorseCodeTree` to do the actual translation, output as a nicely formatted table. Doesn’t have to be alphabetized but that would be nice for the user :smiley:), 2) enter an input textfile name with morse code to decode and output the translated text to the console, and 3) enter in a line of morse code through the console to decode morse code and output the translated text to the console.
> ***NOTE:*** Read the instructions carefully, already know the code from the slides for reading from a text file and doing a preorder traversal cannot directly solve this homework!Β The preorder traversal method may help error check to see if your tree is being built correctly, however!Β Also, you need not implement `Serializable` for your `MorseCodeTree` but you’re encouraged to, since the code is straightforward and very much like the slides.
