C++ Programming Homework 6 Solution

● Define a class hierarchy for Shapes. Define a base class Shape with methods to
draw(), which draws this shape, and area(), which computes and returns the area
of this shape:
○ (20 points) Define an abstract base class, called Shape , with two pure virtual
function ( double area() and void draw() ). Be sure this class has a
constructor which takes parameters to initialize the three data members in
this order (int centerX, int centerY, string name). DO NOT GIVE DEFAULT
PARAMETERS TO THE CONSTRUCTOR PARAMETERS! Be sure area
returns a double as integer would not be precise enough for practical use.
○ (40 points) Derive a total of four classes from Shape: derive three classes
( Circle , Square , and Triangle ) directly from your abstract base class and
make them concrete by providing implementations for the virtual functions
introduced in your abstract base class Shape . The methods for each of
these three classes must actually behave differently from one another
(example: Circle area vs. Square area vs. Triangle area).
Derive the fourth class, Rectangle , from Square and add a width. For draw()
use character graphics. The shapes should resemble the shape defined by
the class.
○ (20 points) Write a class Picture that holds a list of Shapes. Write a method,
called add(Shape *sp) that adds the shape pointed to by sp to this picture.
Also define two polymorphic methods that operate on a Picture: void
drawAll() and double totalArea() . Implement Picture as a LinkedList of
Shapes. Be sure your destructor cleans up your Picture when it dies.
○ (20 points) Write a main program that builds a Picture and fills it with two
triangles, two circles, two squares, and two rectangles (Specified below).
Then have it call drawAll(), then have it print out the totalArea() of the
shapes on that picture.
FirstTriangle: height=5, base=5
SecondTriangle: height=4, base=3
FirstCircle: radius = 5
SecondCircle: radius = 10
FirstSquare: side=5
SecondSqaure: side = 10
FirstRectangle: height = 4 width=8
SecondRectangle: height=8 width=4
/* various pictures of the shapes omitted because they are too hard to draw by
hand */
The total area of the shapes on this picture is 600.199 square units.
HW6 Specifics:
The output shapes may be simple and unimpressive. That’s OK. Do not use any
external libraries for the drawing graphics, simple character graphics is what we want.
You can still draw almost standard shapes with character graphics. E.g, a rectangle
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or
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Put each class (full definition) in a separate header file, but put include guards on each
.h file. You can read about include guards here . Each .h file should include the class it
is derived from. main.cpp will include all the .h files in the correct order (to be
determined by you). Your file organization would look something like this:
hw6.zip
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| - main.cpp
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| - Shape.h
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| - Circle.h
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| - Square.h
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| - Triangle.h
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| - Rectangle.h
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| - Picture.h