Introduction to programming, course exam 19 Oct 2010/AW

At the top of each paper, please write the name of the course and the date
of the exam, your name, student number (or SII number), and your signature. 
Write each reply (1, 2, 3) on its own paper! You may reply in Finnish, 
Swedish or English. If necessary, you may even use all of these languages,
as long as your replies are intelligible.

1. a) An account with an overdraft facility can be positive or negative. 
      Only even Euros are kept in the acocunt. Implement the charge account
      as the class ChAc.

      ChAc-API:

        * public ChAc() creates the object ChAc, with the initial balance of 0 Euros.
        * public ChAc(int saldo) creates the object ChAc, to which the initial
          balance is given as input.
        * With the accessor deposit, you can deposit money in the account.
        * With the accessor withdraw, you can withdraw money from the account.
        * The accessor balance returns the current balance of the account as
          its value.

   b) A foundation has two accounts. One account is for its own money, the other
      one for support funds from the Slot-Machine Association. Let us call the
      accounts "assets" and "backing". The backing account can never be empty.
      The assets account may even be negative. If the account is negative, it
      means that the foundation owes money, if it is positive, the foundation
      has money. Program the class Foundation to implement the foundation. To
      implement the accounts, you must use the class ChAc from problem a.

      Foundation-API:

       * public Foundation(int assets, int backing) creates the object Foundation.
         The initial balance of its accounts are given as parameters.
       * getAssets, getBacking and getBalance return as their values the account
         information of the foundation. The last refers to the overall status of
         the foundation, i.e. the sum of the accounts.
       * public void capitalchange(int amount) changes the balance of the assets
         account according to the parameter.
       * public boolean backingComing(int amount) adds to the backing account
         according to the parameter; only positive backing is accepted. If the
         Slot-Machine Association tries to take away money from the foundation
         as "negative backing", the method will not change the balance and will
         return the value false, otherwise the method returns true.
       * public int transferBackingToAssets(int amount) moves money from the
         backing account to the assets account according to the parameter. If
         there is not enough money in the account to transfer the requested
         amount, what is there, is transferred. If the parameter is negative, no
         transfer is made - we can't call assets backing, can we? As its value, 
         the method returns the amount transferred.
       * public String toString() returns as its value a plain string
         representation of the foundation's status.

   c) Illustrate how to use the class Foundation by implementing the class
      FoundationPresentation with a main program that presents the all-round use
      of the class Foundation. The program does not need to read anything.
                                                                       (15 points)

2. Give clear explanations of the concepts parameter, overloading, encapsulation. 
   Give illustrating examples.
                                                                        (9 points)

3. Create a program that first asks for the number of integers to be input, then
   reads that number of integers into an array, and finally offers the following
   service: One integer at a time is fed into the program, and the program finds
   out whether that integer is in the array. It must use binary search to find
   the answer. You may assume that all the input is valid and acceptable.
                                                                       (12 points)