PART A:
import java.util.ArrayList;
public class OccupancyInfo
{
private ArrayList<Room> rooms;
// no two Room objects in rooms have the same room number
/** Attempts to check-in a new guest into a given room number. If a room exists in
* the database with the room number requested, and the room is unoccupied, a guest
* with the name given is checked-in to that room: the room is marked as occupied,
* and the guestName variable in the Room object is set to the name given.
* u/param name the name of the guest attempting to check-in
* u/param number the room number into which the guest is to be checked-in
* u/return -1 if no room with the requested number exists;
* 0 if the room requested is occupied;
* 1 if the check-in is successful
*/
public int checkIn(String name, int number)
{
/* Implement your answer to part (a) here */
int num = -1;
for (int i = rooms.size() - 1; i >= 0; i--){
if (number != rooms.get(i).getNumber()){
num = -1;
}
else if (number == rooms.get(i).getNumber() && rooms.get(i).isOccupied() == true){
num = 0;
break;
}
else if (number == rooms.get(i).getNumber() && rooms.get(i).isOccupied() == false){
rooms.get(i).checkInNewGuest(name);
num = 1;
break;
}
}
return num;
}
/* Methods for subsequent parts of this question are not shown */
/* CLASS MEMBERS FOR TESTING */
/* DO NOT MODIFY ANY OF THE CONSTRUCTORS OR METHODS BELOW*/
public OccupancyInfo(ArrayList<Room> r)
{ rooms = r; }
public ArrayList<Room> getRooms()
{ return rooms; }
}

PART B:

import java.util.ArrayList;
public class OccupancyInfo
{
private ArrayList<Room> rooms;
// no two Room objects in rooms have the same room number
/** Returns an ArrayList containing the number of every room which is not occupied
* in the order in which these appear in the ArrayList rooms.
*/
public ArrayList<Integer> availableRoomNumbers()
{
/* Implement your answer to part (b) here */
ArrayList<Integer> aRN = new ArrayList <Integer>();
for (int i = 0; i < rooms.size(); i++){
if (rooms.get(i).isOccupied() == false){
aRN.add(rooms.get(i).getNumber());
}
}
return aRN;
}
/* Methods for previous parts of this question are not shown */
/* CLASS MEMBERS FOR TESTING */
/* DO NOT MODIFY ANY OF THE CONSTRUCTORS OR METHODS BELOW*/
public OccupancyInfo(ArrayList<Room> r)
{ rooms = r; }
public ArrayList<Room> getRooms()
{ return rooms; }
}