Introduction to Data Structures and Software Engineering

CS1704 : Summer Session II 2000 : Midterm 1

Question One [20]
  1. List two reasons why we study data structures. [5]

    2. Eliminate size boundaries of fixed-size variables
    More efficient data access techniques

  2. List one advantage and one disadvantage of programming with modules. [5]

    3. Advantage: smaller compilation units => less time for recompilation during debugging
    Disadvantage: hard to keep track of large number of files

  3. List two advantages of object-oriented programming. [5]

    4. Objects are a closer model of the real world so it is easier to convert real-world solutions to computer programs
    Encapsulation and data hiding reduces complexity

  4. Dynamic variables still require a small amount of static storage space. What is this used for? [5]

    5. This space is required to store the address of the memory associated with the dynamic variable

Question Two [20]

Match the following terms with the most appropriate descriptions:

5000 modules, software engineering, design specification, function prototype, #ifdef, global variable definition, constructor, overloading, pointer variable, dereferencing


_ #ifdef ________________	avoid multiple inclusions of one header file

_ pointer variable ______	memory allocated at compile-time for address only

_ global variable defn __	.CPP file

_ software engineering __	problem, design, program, maintain

_ overloading ___________	set of similar functions

_ constructor ___________	automatic function

_ dereferencing _________	getting from an address to the actual data

_ 5000 modules __________	high cost of integration

_ design specification __	structure chart

_ function prototype ____	header file

Question Three [40]
  1. What is a class ? [4]

    2. A class is a data type definition/declaration for an object.

  2. When is a constructor called? What is it usually used for? [6]

    3. It is called when an object is created. It is usually used to initialize the object.

  3. Does a constructor return a value? Why or why not? [6]

    4. No. The constructor is called automatically by the compiler, which would not know what to do with a returned value.

  4. Write out non-inline definitions for all the functions contained within the following class declaration for an OOP model of a planet. SetRadius sets the radius of the planet and GetRadius returns that value. There is a constructor to set initial values and a member function (GetVolume) to compute the object’s volume. The formula to calculate volume from radius is Volume = 4/3 Pi Radius3. [20]
    5. const float Pi = 3.14159265359;

class Planet
{
private:
   double Radius;
public:
   void SetRadius ( double aValue );
   double GetRadius ();
   double GetVolume ();
   Planet ( double aValue );
};


    void Planet::SetRadius ( double aValue )
{
   Radius = aValue;
}

double Planet::GetRadius ()
{
   return Radius;
}

double Planet::GetVolume ()
{
   return Pi * Radius * Radius * Radius * 4 / 3;
}

Planet::Planet ( double aValue )
{
   SetRadius (aValue);
}

  5. In the previous question, we could have used an inline function for SetRadius. How does the compiler handle inline functions differently? [4]

    6. The compiler replaces every call to the function with the (compiled equivalent of the) actual body of the function.

Question Four [20]

Consider the following structure chart for a small program:

  1. Does A ever call E directly? [2]

    2. No

  2. Does A ever call B directly? [2]

    3. Yes

  3. Is it possible for C and F to be in the same module? [2]

    4. Yes

  4. Is it possible for D and F to be in the same module? [2]

    5. Yes

  5. Is K an input or output variable? [2]

    6. Output

  6. Is K a data or control variable? [2]

    7. Data

  7. What type of function is R? [2]

    8. System call

  8. List 3 errors (or inconsistencies) in the structure chart. [6]