/rovio-assignment

Primary LanguageJava

PlushMarket

Plush market is a trading place for all the fluffy plush toys.

In the market you can either sell your plush directly at the current market price or trade it to another one. Each trade can only be done once.

Your goal is to implement functionality, which calculates the optimal plush toy sales strategy:

  • Maximizes the sales price
  • Minimizes the number of trades

Assignment

You need to implement the PlushMarket interface to return the optimal strategy.

public interface PlushMarket {
    String calculateStrategy(String offerJSON, String marketJSON);
}

The interface uses JSON format for both input and response. For the exact format of the input and response JSON check the examples below.

Examples

Example 1

If the offerJSON is

{"plush": "Stella"}

and marketJSON is

{"plushes": [
    {"plush": "RedBird", "price": 80},
    {"plush": "Stella", "price": 90},
    {"plush": "Pig", "price": 75}
],
"trades": [
    {"take": "RedBird", "give": "Pig"},
    {"take": "Pig", "give": "Stella"}
]}

then the response providing the optimal strategy is

{"actions":[
    {"action":"sell","plush":"Stella","price":90}
]}

since the sales price of the Stella is highest, you cannot improve the price by trading.

Example 2

If the offerJSON is

{"plush": "RedBird"}

and the marketJSON is the same as above, then the optimal strategy is

{"actions":[
    {"action":"trade","give":"RedBird","take":"Pig"},
    {"action":"trade","give":"Pig","take":"Stella"},
    {"action":"sell","plush":"Stella","price":90}
]}

since you can trade your RedBird to Pig and then trade the Pig to Stella with sales price of 90 instead of selling it directly at the market price of 80.

Example 3

If the offerJSON is

{"plush": "BlueBird"}

and the marketJSON is the same as above, then the optimal strategy is

{"actions":[]}

since there is no market price nor trades for the BlueBird plush.

Things to remember

  • Work on the assignment as if it was production code worth 10M$
  • Your answer will be graded on the basis of correctness (it works) and code quality (others can see how it works)
  • The solution must be submitted by opening a pull request on the GitHub project repository
  • Include tests in your answer
  • You are free to use any library from Maven Central
  • Pay attention to the readability of your code