Kudomon GO!

Credit Kudos' Technical Challenge.

What is this challenge for?

We want to understand the way you think about problems, and how you write code to tackle them. We’re not looking for the most efficient algorithmics, we’re looking for the simplest solution.

We’re not going to give much in the way of guidance as to the specifics of implementation - if you think a class needs an attribute or a method, you go ahead and do it. You’re in charge.

How should solutions be presented?

Ideally, solutions will be vanilla ruby code with tests. rails is optional. If you're more comfortable in another language, feel free to use that!

To submit your response, fork this repo and raise a pull-request containing your answer.

So, what’s the challenge?

Imagine that all around us, in a virtual world, are virtual creatures (Kudomon) that you can catch and collect.

Your task is to write a program that allows a Trainer (like you) to interact with these Kudomon. The challenge is broken down into four parts.

Part 1

Define domain classes to model this application.

There are many different species of Kudomon, each having a type. Here are some (invented) examples:

• species: "Sourbulb", type: :grass
• species: "Mancharred", type: :fire
• species: "Chikapu", type: :electric

Other types include :water, :rock and :psychic. Feel free to invent your own species using these six types!

Both Trainers and Kudomon need to have a Position, so we can know how close different entities are to each other.

Part 2

Gotta catch ‘em all!

In this part we’ll implement the means for a Trainer to catch a Kudomon and add it to their collection.

First, we need to know which Kudomon are nearby to a Trainer. Write code to calculate this. How you define “nearby” is completely up to you.

A Trainer can catch nearby Kudomon and add them to his/her collection. Write code to allow this.

Part 3

Multi-player

Now we’re going to introduce the idea that multiple Trainers can try and catch Kudomon at the same time.

Scenario:

1. I’m sat at my computer and I see a Kudomon I want to catch. I try to catch it.
2. At the exact same time, my neighbour Freddy sees the same Kudomon and also tries to catch it.
3. Freddy succeeds and adds the Kudomon to his collection before I’ve finished catching it.
4. I am unable to catch the Kudomon.
5. I now feel sad.

How can we avoid this situation? Does your program handle this elegantly? If not, how can you change it to allow for this feature?

Now imagine instead of just two people, it’s 10,000 people cramming into Central Park to catch the same Kudomon - would the same solution work then? What are the limitations? How could you mitigate?

Part 4

Be the very best!

For some reason, Kudomon allow their Trainers to make them battle each other until one of them is knocked out.

Add the concept of a Battle between two Kudomon to your code. Amend your code to take into account that Kudomon have health_points or hp and combat_points or cp.

Write code for a fight with the following mechanics:

1. A randomly chosen Kudomon goes first.
2. Until one of the Kudomon is knocked out (i.e. when health_points <= 0), both battling Kudomon take it in turns to inflict damage on the other. The amount of damage is equivalent to their combat_points.
3. The fight should return the winner.

To make it more interesting, certain types Kudomon are SUPER_EFFECTIVE against other types. For example, a :fire Kudomon will beat a grass type easily, and a :water type will extinguish a :fire type.

You can characterise the strengths of each type as follows:

:water > :fire > :grass > :rock > :electric > :water

(:psychic is good against everything except other :psychics.)

Amend your code to take this dynamic into account.