Description
Q1. Write a function
string repeatString(const string & str, unsigned int n) { . . . }
which takes a C++ string str and returns the string repeated n times. Test your function by using the following test code in main():
cout << repeatString(“echo! “,5) << endl;
which should print out
echo! echo! echo! echo! echo!
Q2. Write a function
void printBigX(int N) { . . . }
Which uses a for loop nested inside another for loop to print out a ‘big X’ of size N x N characters. Examples of the required output are shown
below.
Calling printBigX(7) should print:
X X
X X
X X
X
X X
X X
X X
Calling printBigX(12) should print:
X X
X X
X X
X X
X X
XX
XX
X X
X X
X X
X X
X X
14/08/2020 2020_EE219: Assignment 3
https://loop.dcu.ie/mod/assign/view.php?id=1227276 2/7
Q3. Write a C++ class called Book. A book has an author, a title and a year which are stored as private data members. Use C++ strings to store
these members. Book should have a constructor to initialize the three values when creating a Book object. It should also have three public
methods getAuthor(), getTitle() and getYear() which return the current value of the author, title and year respectively.
Q4. Write a function (not a method of a class)
int countBooksByAuthor(Book bookList[], int size, string author) { … }
which takes an array of Book objects (your class from Q3) and counts the number of books by a given author. The search should count partial
matches of an author’s name. E.g. if searching on “Stroustrup”, books by “B. Stroustrup” or “Borjn Stroustrup” should be counted. You may make
use of the find() method of the C++ string class. Test that your function operates correctly using this test code in main():
Book books[] = {
Book(“B. Stroustrup”, “A Tour of C++”, “2018”),
Book(“J. Bloch”, “Effective Java”, “2018”),
Book(“B. Stroustrup”, “The C++ Programming Language(Fourth Edition)”, “2013”),
Book(“B. McLaughlin, G. Pollice, D. West”, “Head First Object Oriented Analysis and Design”, “2006”),
Book(“B. McLaughlin”, “Java and XML”, “2006”) };
string searchAuthor = “McLaughlin”;
cout << “There are ” << countBooksByAuthor(books, 5, searchAuthor) << ” books by author ” << searchAuthor << endl;
Q5. Write a C++ class called Complex which represents a complex number. It should have two private data members to store the real and imaginary
part of the number, a constructor that takes two values to initialize the complex number and a print() method which prints out the complex
number in the form “a + bi”. Test your class from main() using the following code:
Complex c1(2.7,–5.2);
c1.print(); // should print “2.7 – 5.2i”
Q6. Add the following two methods as member functions of your Complex class
Complex conj() { … }
which returns the complex conjugate of the complex number as another Complex object, and
Complex multiplyBy(const Complex & z) { … }
which returns the complex number multiplied by a given complex number z. Your class must function correctly when the following test code is run
from main():
Complex c1(2.7,–5.2);
c1.print(); // prints “2.7 – 5.2i”
Complex c2 = c1.conj();
c2.print(); // prints “2.7 + 5.2i”
Complex c3 = c1.multiplyBy(c2);
c3.print(); // prints “34.33 + 0i”
Q7. Write a class called Point that represents a 2-dimensional point. Its X and Y coordinates should be stored as private data members. It should
have a default constructor and a constructor taking two parameters to initialize the point’s coordinates with given X and Y values. It should also
have a public method of the following form:
double distanceTo(const Point & p)
which returns the distance from this point to another point p. Your class must operate correctly with this test code (when called from main())
Point p1(1.0,1.0);
Point p2(2.0,2.0);
cout << “Distance between points is ” << p1.distanceTo(p2) << endl;
which should print the distance as 1.41421
Q8. Write a Polygon class which represents a polygon consisting of a sequence of 2D points. A polygon can have up to a maximum of 10 points.
The class should store points as an array of Point where Point is your class of Q7. Your polygon class should have a default constructor and the
following public member functions:
bool add(Point p) { … }
14/08/2020 2020_EE219: Assignment 3
https://loop.dcu.ie/mod/assign/view.php?id=1227276 3/7
which adds a new point to the polygon. This method returns false if the polygon already has 10 points when the method is called, returns true
otherwise.
double length() { … }
which calculates and returns the perimeter length of the polygon. The points stored in the polygon are assumed to be in order around its
perimeter. Your class must operate correctly when used from main() as follows:
Polygon poly;
poly.add(Point(0,0));
poly.add(Point(1,0));
poly.add(Point(1,1));
poly.add(Point(0,1));
cout << poly.length() << endl; // should return length of 4
Q9. Write a class CyclicString which stores a C++ string whose characters can be retrieved in sequence by successively calling a next() method on
the object. When the end of the string is reached, a call to next() will start over at the being of of the string. Your class must operate correctly with
the following test code in main():
CyclicString s(“Repeat Me!”);
for (int i=0; i<50; i++)
cout << s.next();
This should print out Repeat Me!Repeat Me!Repeat Me!Repeat Me!Repeat Me!
Submission status
Submission
status
Submitted for grading
Grading status Graded
Due date Monday, 2 March 2020, 6:00 PM
Time remaining Assignment was submitted 27 secs late
Grading criteria
This is the assignment marking scheme for EE219 assignments.
Question 1:
Question 2:
Solution is
missing or no
reasonable
attempt.
0 points
An attempt has
been made along
the right lines
but the
functionality and
code output are
not correct.
2.5 points
Solution is
almost correct
but there are
obvious flaws,
some
requirements
stated in
question are not
handled or
function/class
has wrong form.
5 points
Solution almost
perfect,
function/class
has correct form
and functionality,
but the code is
not as efficient as
it could be.
7.5 points
Solution
perfectly correct
and code
efficiently
implemented.
10 points
Solution is
missing or no
reasonable
attempt.
0 points
An attempt has
been made along
the right lines
but the
functionality and
code output are
not correct.
2.5 points
Solution is
almost correct
but there are
obvious flaws,
some
requirements
stated in
question are not
handled or
function/class
has wrong form.
5 points
Solution almost
perfect,
function/class
has correct form
and functionality,
but the code is
not as efficient as
it could be.
7.5 points
Solution
perfectly correct
and code
efficiently
implemented.
10 points
