Apartment Management

The Coconut Grove Palace is a new block of super-luxury apartments being built at the end of Pan American Drive in Coconut Grove. The block has two floors, with three apartments on the first floor and two apartments on the second floor. These are such good apartments that they have all been sold pre-construction, each to a couple (weird, but that's what happens in a society that places more emphasis on image than on family). Anyway, the condo association has agreed on the following rules:

No more than four occupants per apartment, ever.
No more than eight people per floor, ever.
The building maintenance costs, which are $5000, will be spread across the apartments according to the number of people, rather than the apartment size. For example, if there are 30 people living in the building, and there are 3 people in an apartment, their maintenance will be $500.

The condo association wants a simple program to help them manage Coconut Grove Palace. The program must keep track of the number of people living in each of the apartments, and provide reports on individual apartments and the building as a whole. The program must be menu driven, with options to:

Report the occupancy and maintenance for a specified apartment.
Report the occupancy and maintenance for all apartments.
Change the number of people living in a a specified apartment. This function must check and disallow occupancy changes that violate the condo association rules.
Exit

Here what a sample run should look like (with the keyboard input shown in italics) ...

Welcome to Coconut Grove Palace
(A)partment, (B)uilding, (P)eople, e(X)it : b
Floor 1 Apt 1 : 2 people : $1000.00 maintenance
Floor 1 Apt 2 : 2 people : $1000.00 maintenance
Floor 1 Apt 3 : 2 people : $1000.00 maintenance
Floor 2 Apt 1 : 2 people : $1000.00 maintenance
Floor 2 Apt 2 : 2 people : $1000.00 maintenance
(A)partment, (B)uilding, (P)eople, e(X)it : p
Please enter floor number     : 1
Please enter apartment number : 3
How many people will there be : 4
(A)partment, (B)uilding, (P)eople, e(X)it : b
Floor 1 Apt 1 : 2 people : $ 833.33 maintenance
Floor 1 Apt 2 : 2 people : $ 833.33 maintenance
Floor 1 Apt 3 : 4 people : $1666.67 maintenance
Floor 2 Apt 1 : 2 people : $ 833.33 maintenance
Floor 2 Apt 2 : 2 people : $ 833.33 maintenance
(A)partment, (B)uilding, (P)eople, e(X)it : a
Please enter floor number     : 1
Please enter apartment number : 3
Floor 1 Apt 3 : 4 people : $1666.67 maintenance
(A)partment, (B)uilding, (P)eople, e(X)it : p
Please enter floor number     : 2
Please enter apartment number : 2
How many people will there be : 7
ERROR: Too many people for an apartment
(A)partment, (B)uilding, (P)eople, e(X)it : p
Please enter floor number     : 1
Please enter apartment number : 1
How many people will there be : 4
ERROR: Too many people for the floor
(A)partment, (B)uilding, (P)eople, e(X)it : p
Please enter floor number     : 2
Please enter apartment number : 1
How many people will there be : 3
(A)partment, (B)uilding, (P)eople, e(X)it : a
Please enter floor number     : 4
Must be in range 1 to 2 : 1
Please enter apartment number : 6
Must be in range 1 to 3 : 3
Floor 1 Apt 3 : 4 people : $1538.46 maintenance
(A)partment, (B)uilding, (P)eople, e(X)it : b
Floor 1 Apt 1 : 2 people : $ 769.23 maintenance
Floor 1 Apt 2 : 2 people : $ 769.23 maintenance
Floor 1 Apt 3 : 4 people : $1538.46 maintenance
Floor 2 Apt 1 : 3 people : $1153.85 maintenance
Floor 2 Apt 2 : 2 people : $ 769.23 maintenance
(A)partment, (B)uilding, (P)eople, e(X)it : x

You must ...

Do a top down design for this problem, producing a structure chart (it's OK to draw it by hand).
Do a design for the program.
Implement the program in Java.
- Use a two dimensional array to store the number of people in each apartment.
- Where possible, make the program idiot proof, i.e., ensure that user input is appropriate before processing it.