import java.util.*;

// Class to help test question 5.
// Write your solution to twoFlightsAway in this class.
// It will not compile until you add your method!
public class TestQ5 {
    public static void main(String args[]) {
        // Build up map from example
        Map<String, Set<String>> flights = new HashMap<String, Set<String>>();
        addFlights(flights, "Cairo", "Ottawa", "Rome");
        addFlights(flights, "Ottawa", "Cairo", "Seattle", "Tokyo");
        addFlights(flights, "Pyrus");
        addFlights(flights, "Rome", "Cairo");
        addFlights(flights, "Seattle", "Ottawa", "Tokyo");
        addFlights(flights, "Tokyo", "Ottawa", "Seattle");

        Map<String, Set<String>> twoAway = twoFlightsAway(flights);
        System.out.println(twoAway);

        checkEquals("Example from spec", twoFlightsAway(flights).toString(),
                "{Cairo=[Seattle, Tokyo], Ottawa=[Rome], Rome=[Ottawa], Seattle=[Cairo], Tokyo=[Cairo]}");
    }

    // Adds flight information from the starting point to each destination in destinations (an array)
    public static void addFlights(Map<String, Set<String>> flights, String start, String... destinations) {
        flights.put(start, new HashSet<>());

        for (String dest : destinations) {
            flights.get(start).add(dest);
        }
    }

    // Checks if the expcted value matches the value received. Prints out information
    // (including a description) explaining what was tested and if it succeded.
    // Also prints a note in the case of test failure to indicate any special cases.
    public static <E> void checkEquals(String description, E received, E expected) {
        System.out.print("Testing " + description + " ...  ");
        if (expected.equals(received)) {
            System.out.println("Passed!");
        } else {
            System.out.println("Does not match!");
            System.out.println("   Received: " + received);
            System.out.println("   Expected: " + expected);
        }
    }
}