instructions.md

The HTTP Billion Dollar Question

Problem Statement

You have been asked to find the top x billionaires by net worth in a given set of countries (number of countries = N). To implement that, you have been given access to an API that returns the details of the billionaires by country.

To simplify accessing the API, you can use a predefined client connector to connect to the API which returns details of the billionaires by country.

import ballerina_exercism/http_billion_dollar_question.billionarehub_server as _;
import ballerina_exercism/http_billion_dollar_question.billionarehub_client as billionarehubClient;

type Billionaire record {
    string name;
    float netWorth;
};

public function getTopXBillionaires(string[] countries, int x) returns string[]|error {
    billionarehubClient:BillionareClient cl = check new();

    // TODO Write your logic here
    return [];
}

Constraints

• 1 <= N <= 5
• 1 <= x <= 10

Example 1

Input

Countries: ["United States"]
Limit: 3

Output

["Elon Musk", "Jeff Bezos", "Bill Gates"]

Example 2

Input

Countries: ["China", "India"]
Limit: 5

Output

["Mukesh Ambani","Zhong Shanshan","Ma Huateng","Colin Huang","Pony Ma"]

Test Environment

• Use bal test to run and test your implementation.

Hints

• http_billion_dollar_question package's billionarehub_client module can be used to invoke the get billionaires by country API. You can use the getBillionaires("<country>") remote method specifically.
• You can find the richest people per country first and then combine them to find the top x
• Query expressions will be convenient for filtering and sorting