581325-0 Introduction to Programming, course examination 16.10.2006/AW

1. Explain shortly and clearly the following concepts: the type of a variable, parameter, encapsulation, toString()-method, index.

                                                               (18 points)
   

2. A juice automata has two tanks: one for water and one for concentrated juice. Juice is produced by mixing 1/10 concentrated juice with 9/10 water.

   Implement the juice automata as a class JuiceAutomata. (The constructor and accessors interpret negative parameter values as zero.)

   • public JuiceAutomata(double waterTankCapacity, double concentrationTankCapacity) creates a juice automata with tank capacities given as parameters. The tanks are empty at the beginning.

   • public double addWater(double amount) adds water to the water tank. The method returns the amount of water that could not be added to the water tank. It is zero if all could be added.

   • public double addConcentration(double amount) adds concentration to the concentrated juice tank. The method returns the amount of concentration that could not be added to the tank. It is zero if all could be added.

   • public boolean produceJuice() produces juice using water and concentrated juice. The size of one portion is 0.2 units. The method returns false, if there is lack of raw materials. The method returns true, if it is possible to produce juice. As a matter of fact the method only tries to use 0.18 units of water and 0.02 units of concentrated juice!

   • public String toString() returns a clear String representation of the state of a JuiceAutomata object.

   Program also a main method to show, how the constructor and the methods are used.

                                                              (16 points)
   

3. Make a program that first asks the amount of integer numbers to be input, then asks that amount of numbers one by one and assingns them into an array. After this the program provides the following service:

   The program is given an integer one by one, and the program finds out, whether that integer is to be found in the array. You must use the Binary Search for finding the answers. All the input numbers should be in the range 1-100000, except the number 0, which ends all the questioning.

   You may assume that all the input are valid integers, but their values must be checked and possible must be errors reported.

                                                               (16 points)