package space; import java.util.ArrayList; public class Mission implements Comparable { private String destination; private float cost; public Mission(String destination, Float cost) { this.destination = destination;
package space;
import java.util.ArrayList;
public class Mission implements Comparable
{
private String destination;
private float cost;
public Mission(String destination, Float cost)
{
this.destination = destination;
this.cost = cost;
}
public String getDestination()
{
return destination;
}
public float getCost()
{
return cost;
}
// Compare by cost, then by destination.
public int compareTo(Mission that)
{
}
// Let compareTo() do the work. This method should just be 1 line.
public boolean equals(Object x)
{
}
// As you saw in lecture, create an ArrayList
// cost to the list. Return the list's hash code.
public int hashCode()
{
}
public String toString()
{
return "Mission to " + destination + " will cost " + cost;
}
}
package space;
import java.util.*;
/*
* During iteration, missions that cost
* Then expensive missions (that cost >= $1 trillion) are presented in the natural sorting order
* of the Mission class.
*/
public class MissionOrganizer implements Iterable
{
private final static float ONE_TRILLION = 1.0e12f;
// Insert declarations for 2 collections: 1 for cheap missions, 1 for expensive missions.
MissionOrganizer()
{
// Create the 2 mission collections.
}
// Returns true if either cheapMissions or expensiveMissions contains m.
public boolean contains(Mission m)
{
}
// Only adds if mission is not yet contained in this collection. Adds to
// cheapMissions or expensiveMissions, depending on whether the mission's
// cost is = $1 trillion.
public void add(Mission mission)
{
}
// Create an ArrayList. Add all the cheap missions to the ArrayList; then
// add all the expensive missions. (Hint: look in the API page for ArrayList for a
// method that adds all members of a collection.) The ArrayList will then contain
// all the missions, in the desired order. Return the ArrayList's iterator. This
// technique was shown in lecture, in the presentation of the Roster class, and will
// be on the final exam.
public Iterator iterator()
{
}
// All costs are uneducated guesses.
private final static Mission[] TEST_MISSIONS =
{
new Mission("Alderaan", 1E16f),
new Mission("High Earth Orbit", 3E8f),
new Mission("Moon", 2.5E10f),
new Mission("Alpha Centauri", 1E14f),
new Mission("Asteroids", 7E11f),
new Mission("Uranus", 9E11f),
new Mission("Jupiter", 2E11f),
new Mission("Low Earth Orbit", 1E8f),
new Mission("Cetaganda", 13E16f),
new Mission("Mars", 8E10f),
new Mission("Neptune", 1.0E12f),
new Mission("Barrayar", 1E16f),
new Mission("Saturn", 8E11f),
};
public static void main(String[] args)
{
MissionOrganizer organizer = new MissionOrganizer();
for (Mission m: TEST_MISSIONS)
organizer.add(m);
for (Mission m: organizer)
System.out.println(m);
}
/*
Expected output:
Mission to High Earth Orbit will cost 3.0E8
Mission to Moon will cost 2.49999995E10
Mission to Asteroids will cost 6.9999998E11
Mission to Uranus will cost 8.9999999E11
Mission to Jupiter will cost 1.99999996E11
Mission to Low Earth Orbit will cost 1.0E8
Mission to Mars will cost 8.0E10
Mission to Saturn will cost 7.9999998E11
Mission to Neptune will cost 1.0E12
Mission to Alpha Centauri will cost 1.0E14
Mission to Alderaan will cost 1.00000003E16
Mission to Barrayar will cost 1.00000003E16
Mission to Cetaganda will cost 1.30000001E17
*/
}
Mission.java This simple class contains the destination and cost of a space mission Complete 3 methods in this class: compareTo0 Compare by cost. If costs are equal, compare alphabetically by destination. equals0- Implement this just a few lines, 1 of which calls compareTo0. hashCode0 Do this as you saw in lecture, by creating an ArrayList
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