Mastermind

1. This implementation of mastermind contain two players i.e. ComputerPlayer and HumanPlayer
2. You are the HumanPlayer
3. You can choose to be either code breaker or code creator
4. If you choose to be code guesser then ComputerPlayer will create code and you'll get 11 tries to guess the code.
5. If you can guess the secret code in 11 tries then you win the game and the game will end with a winning message.
6. If you can't guess the code in 11 tries you lose the game and the game will end with a losing message.
7. If you choose to be the code creator, then write your code on a piece of paper.
8. ComputerPlayer will start guessing your code and everytime Computer makes a guess, look at your code(where you wrote it in step 7) and provide feedback.
9. ComputerPlayer will work under the assumption that you'll always provide correct feedback.
10. ComputerPlayer will always win and will be able to guess the code in atmost 5 tries. Provided that the feedback you provide is correct.
11. It uses Knuth's algorithm to guess it in atmost 5 tries. More details on the algortihm are here

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Click to know about How to Play Mastermind

Code Creator

If you want to be the code creator then press 2. Write your code on paper and every time ComputerPlayer make a guess look at your code and provide feedback. Take some time but do provide correct feedback. In the above GIF I created the code ["Red", "Blue", "Green", "Yellow"]. I kept on providing feedback to Computer based on this code and the ComputerPlayer was able to guess the original code in 4 tries.

Code Breaker

If you want to be the code breaker then press 1. Provide the guess in the format specified in the above peg.

Play the Game

To Play the mastermind :

1. Go to this link.
2. Click on the green Fork button in the top upper right corner.
3. Select blue Fork repl button.
4. Now Click the green Run button.
5. You'll be prompted to choose between code creator or code breaker
6. Enter 1 if you want to guess the code created by the ComputerPlayer
7. Enter 2 if you want the ComputerPlayer to guess your secret code
8. KEEP REPEATING AND HAVE FUN!!

Problems that I Faced

1. Implementing the functionality for white feedback peg was difficult. For red feedback peg it was way easier, just check the corresponding pegs in both code and guess and if they are same then increment a counter variable for it. I ended up using red peg feedback data and method max_peg_count to indirectly get get the white feedback data.

2. Whle implementing Knuth's Mastermind Algorithm to remove codes from the set of all possible 1296 codes, I was using each method on set while simultaneously updating my set which led to my possible codes leakage.

Lessons Learned

1. Always write pseudocode first. It saves time and helps to find fault in your logic. You may have a strong temptation to just write the code directly but refrain from doing so. Write pseudocode and verify it against some examples. Once you have done that you can be sure that whatever error comes now is an implementation problem.

2. Don't think about refactoring and writing new piece of functionality together. Focus on one thing at a time.

3. Always create a functionality outline via functions only then begin to fill those functions. The other way around is too confusing for me. Writing individual functions first and then thinking about how to piece them together to achieve the desired functionality wastes too much time and it doesn't give a good feel of data flow.

4. Tests are awesome. Everytime I wrote a functionality, I feared that it might break something. I had to check if everything was working manually which took too much time. So why didn't I write tests?? I haven't studied them in Ruby yet but had prior exposure to them in Java.