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Exercises from

"Programming Principles and Practice Using C++"

Chapter 1

1. Compile a list of daily activities involving the use of computers.
2. Pick a favourite profession and the activities within it involving the use of computers.
3. Swap the lists from Ex 1 and Ex 2 with a friend and compare results.
4. List of activities not possible without computers.
5. List of programs that you have used.
6. List of activities not involving computers.
7. Five tasks for which computers will be used in the future.
8. Why do you like to be a programmer? ($100 < words < 500$)
9. What other role in computer industry do you like to play?
10. Do you think computers will ever be developed to be conscious, thinking, capable of competing with humans?
11. List of characteristics that good programmers share.
12. Identify five applications for computer programs mentioned in the chapter and one that you want to participate in.
13. How much memory would it take to store: this page, text, Shakespeare's work. (1 byte == 1 character; Estimate 20% precision)
14. How much memory (main, disk) does your computer have?

Chapter 2

1. Print "Hello, programming!\nHere we go!".
2. Write pseudo code (instructions) directing "the computer" upstairs to the bathroom.
3. Write pseudo code (instructions) directing "the computer" from your house/dorm to work/university.
4. Write instructions for a food cooking recipe.
5. Write definition of each of the new terms covered in the first chapter.

Chapter 3

1. Do all Try This examples in the chapter.
2. Miles to kilometers converter.
3. Check compiler response to illegal variable names (identifiers).
4. Define and read two ints. Find and print their min, max, sum, difference, product and ratio.
5. Redo the Exercise 4 with floating point number variables double.
6. Read three ints and list them in increasing order.
7. Redo Exercise 6 with strings.
8. Check if int is odd or even.
9. Read an int as digit / name and print it as name / digit.
10. Read an operation (+, -, *, /) and two (double) values and print the result. (Use if statements).
11. Read pennies, nickels, dimes, quarters and half dollars and print total sum of cents.

Chapter 4

1. Do all Try This examples in the chapter.
2. Find median (element in the middle of the sorted set). Modify 4.6.2
3. Read double values and store them into a vector. Find total sum, mean of all elements, min and max.
4. Write a number guessing game. (manual Binary seach using if statements).
5. Implement a simple calculator with few operations $(+, -, *, /, %)$.
6. Store the names of the digits [0, 9] in a vector and use it to convert digit to its name.
7. Modify Exercise 5 to accept either single digit or its name.
8. Calculate Exponential growth after n turns.
9. Largest value held in int or double, overflow.
10. Implement a game "Rock, Paper, Scissors.". (use switch statements)
11. Find prime numbers within $[1, 100]$. (Use vector that holds current previous primes.)
12. Find prime numbers within $[min, max]$.
13. Implement Sieve of Eratosthenes within $[1,100]$.
14. Modify Exercise 13 to interval $[min, max]$.
15. Find first n primes.
16. Find the mode of a sequence of positive ints.
17. Find min, max and mode of sequence of strings.
18. Solve the quadratic equation with coefficients a, b and c.
19. Read name and value pairs. Check name uniqueness.
20. Modify Exercise 19, so that when you type name it prints its value.
21. Modify Exercise 19, so that when you type an int value it prints the names with that score.

Chapter 5

1. Do all Try This examples in the chapter.
2. Debug existing Celsius to Kelvin converter.
3. Choose appropriate min value and modify Ex. 2.
4. Handle the errors within ctok().
5. Write a Kelvin to Celsius converter.
6. Write a Celsius $<=>$ Fahrenheit converter. (Estimate result.)
7. Solve the quadratic equation, throw an exception if discriminant < 0.
8. Read ints (quit with |), store them in a vector and prompt the user to sum n of them.
9. Modify Ex. 8 and display error if result can't be stored in int.
10. Redo Ex. 8 with values of type double. Calculate the differences of adjacent elements.
11. Print the first n Fibonacci numbers. Find largest Fibonacci stored in int.
12. Implement "Bulls and Cows".
13. Redo Ex. 12, but let each time the numbers be random. (Use rand() and srand())
14. Read (day-of-the-week, value) pairs and store each day in a vector<int>. Print each day and its values.

Chapter 6

1. Do all Try This examples in the chapter.
2. Modify the calculator to evaluate expressions containing $(,)$ and ${,}$.
3. Add factorial operator !.
4. Rework Ex. 19 Ch. 4 using a class Name_value.
5. Expand the English Grammar from 6.4.1 to include the.
6. Write a program that checks if sentence is correct according to the English Grammar.
7. Write a Grammar for Logical Epxressions.
8. Redo "Bulls and Cows" from Ex. 12 Ch. 5, to use four letters instead of four digits.
9. Write a program that reads digits and composes them into integers.
10. Calculate permutations P(a, b) and combinations C(a, b).

Chapter 7

1. Allow underscore _ in the names of the user defined variable in the calculator.
2. Allow used defined variable value reassignment, by introducing an assignment operator=.
3. Allow the definition of const variables.
4. Define class Symbol_table and rewrite the calculator to use it.
5. Print result at newline \n.
6. Provide help function in the calculator.
7. Change help and quit commands.
8. Fix the calculator grammar and add comments (document the code).
9. Define a class Table and rewrite the calculator to use it.
10. Suggest three improvements and implement one.
11. Modify the calculator to operate on int only.
12. Discuss the possible source of problems of introduction of assignment operator=.
13. Revisit two programs from Ch. 4 and Ch. 5, clean and comment them.

Chapter 8

1. Modify the calculator to make the input stream an explicit parameter. Give Token_stream constructor a istream& parameter.
2. Write a function print() that prints a vector of ints; Include a string parameter label.
3. Find n Fibonacci numbers and store them in a vector. Use function print() from Ex. 2 to print them.
4. Find the largest Fibonacci number stored in int.
5. Write a function that reverses the int elements of a vector.
6. Redo Ex. 5 using strings.
7. Read five names and five ages. Sort the names and match the ages. Print the result.
8. Implement a simple function randint().(See Knuth, The Art of Computer Programming, Volume 2)
9. Write a function rand_in_range(int a, int b) that generates a pseudo-random number within $[a, b)$, using randint().
10. Write a function that calculates the sum of the products of the elements of two vectors. (Allow one vector with smaller size).
11. Write a function maxv() that returns the largest element of a vector argument.
12. Find min, max, mean and median of vector arguments. Return the result using struct or by passing by reference.
13. Improve print_until_s() from 8.5.2. Test it. Write a function print_until_ss() that prints until the second occurrence of its argument quit.
14. Write a function that takes a vector<string> argument and returns vector<int> containing the number of character in each string. Also find longest and shortest, lexicographically first and last strings.
15. Can we declare a non-reference function argument const? Why would we? Test it.

Chapter 9

1. List sets of plausible operations for the examples of real-world objects in §9.1 (such as toaster).
2. Design and implement a Name_pairs, holding (string name, double age). Provide sort() operation.
3. Replace Name_pair::print() with a (global) operator<< and define == and != for Name_pairs.
4. Indent the code from §8.4.
5. Implement a class Book, such as you can imagine as part of software for a library; with members for the ISBN, title, author, and copyright date. Create appropriate member functions.
6. Add operators ==, << for the class Book.
7. Create an enum type for the class Book called Genre. Have the types be fiction, nonfiction, periodical, biography, children.
8. Create a class Patron for tlle library. The class will have a user's name, library card number, and library fees (if owed). Create appropriate member functions.
9. Create a class Library. Include vectors of Books and Patrons. Include a struct called Transaction. Have it include a Book, a Patron, and a Date. Create appropriate member functions.
10. Implement leapyear() from §9.8.
11. Design and implement a set of useful helper function for the class Date such as next_workday() and week_of_year().
12. Change the representation of a Date to be the number of days since January I, 1970 (known as day 0), represented as a long, and reimplement the functions from §9.8.
13. Design and implement a rational number class Rational.
14. Design and implement a class Money for calculations involving dollars and cents where arithmetic has to be accurate to the last cent using the 4/5 rounding rule.
15. Refine the class Money by adding a currency. Provide a conversion table.
16. Give an example of a calculation where a Rational gives a mathematically better result than Money.
17. Give an example of a calculation where a Rational gives a mathematically better result than double.

Chapter 10

1. Sum of all the numbers in a file of whites space-separated integers.
2. Creates a file of data in the form of the temperature Reading type defined in §10.5. Fill the file with at least 50 temperature readings.
3. Create a program that reads the data created in Exercise 2 into a vector and then calculates the mean and median of the temperatures in your data set.
4. Modify Exercise 2 to include temperature unit suffix C - Celsius or F - Fahrenheit. Modify the function from Exercise 3 to firstly convert the temperature in Fahrenheit before calculating the statistics.
5. Write the function prin_year() mentioned in §1O.11.2.
6. Define a Roman_int class for holding Roman numerals (as ints) with a operator<< and >> . Provide Roman_int with an as_int() member.
7. Make a version of the calculator from Chapter 7 that accepts Roman numerals.
8. Write a program that accepts two file names and produces a new file that concatenates the two files.
9. Write a program that takes two files containing sorted white space-separated words and merges them, preserving the order.
10. Add a command from x to the calculator from Chapter 7 that makes it take input from a file x. Add a command to y that makes it write its output (both standard output and error output) to file y. Write a collection of test cases based on ideas from §7.3 and use that to test the calculator.
11. Write a program that produces the sum of all the white space-separated integers in a text file.
12. Write a program that given a file name and a word outputs each line that contains that word together with the line number.

Chapter 11

1. Read a file, convert to lower case and write to another file.
2. Remove all the vowels from a text file.
3. Write a program that correctly interprets the base prefixes of integers, i.e. decimal (none), octal (0), hexadecimal (0x), converts them to decimal and prints them in a table in their initial and final format.
4. Read a string and classify each of its characters, e.g. isalpha(), isspace(), etc.
5. Replace punctuation with white space.
6. Modify Ex. 5 to replace don't with do not and can't with cannot; to leave hyphens in between words intact.
7. Use the knowledge from the previous exercises to create a dictionary from a multi-page text.
8. Read and write a binary file.
9. Write a function that accepts a string and returns a vector holding all the white space separated sub-strings of the argument.
10. Expand Ex. 9 to include sub-string separation at any character passed as an additional argument.
11. Reverse the order of characters in a text file.
12. Reverse the order of words (white space separated) in a text file.
13. Perform character classification on the contents of a text file.
14. Read a file containing integers, format them to scientific representation with precision up to the eight digit after the decimal point and write them to another file, four per line in fields of width of 20 characters.
15. Read a file containing integers, sort, count write the result in a table in another file.

Chapter 12

1. Drill: Introduction to reduced GUI based on FLTK: include needed libraries, create Simple_window.
2. Create a rectangle using class Rectangle and class Polygon, use different colours.
3. Draw a Rectangle and place a Text object inside it.
4. DraW your initials in different colours.
5. Draw a Checkers board, with white and red squares.
6. Draw a red 1/4-inch frame around a rectangle that is 3/4 the height and 2/4 the width of the screen.
7. Draw a Shape not matching the size of the window and Window not matching the size of the of the screen.
8. Draw a picture of a house.
9. Draw the Olympic five rings.
10. Display an image and manipulate it.
11. Draw the file diagram of Chapter 12.8, describing the hierarchy of source code dependencies.
12. Draw a series of polygons, one inside the other.
13. Draw a "star-like" pattern by connecting points of super-ellipse.
14. Draw super-ellipses of multiple colours.

Chapter 13

1. Drill: Introduction to Graph_lib members: draw Simple_window, grid, Rectangle & Image objects.
2. Define an Arc which is a part of an Ellipse. Hint: fl_arc().
3. Draw a box with rounded corners. Define a class Box, consisted of four lines and four arcs.
4. Define class Arrow that draws a line with an arrowhead.
5. Define functions n(), s(), e(), w(), center(), ne(), se(), sw(), nw(). Each takes a Rectangle as argument and returns a Point. These functions define "connection points" on and in the rectangle.
6. Connection points with Circles and Ellipses.
7. Write a program that draws a class diagram depicting dependency hierarchy.
8. Make a RGB colour chart.
9. Create a class Hexagon, where centre and distance from the centre to a corner point are the constructor arguments.
10. Tile a part of a window using `Hexagon'; use at least six hexagons.
11. Define a class Regular_Polugon. Use the centre and the number of sides (> 2) as a constructor arguments.
12. Draw a 300 X 200 Ellipse, a 400 - pixels - long x axis and 200 - long y axis through the centre of the ellipse. Mark the foci. Mark a point on the ellipse and not on the axis and connect it to the foci with Lines.
13. Draw a Circle. Move a Mark on the circle each time Next is pushed.
14. Draw the RGB colour chart without the lines around the colours.
15. Define a Right_Triangle class. Draw an octagonal shape using eight right triangles of different colour.
16. Tile a window with small right triangles.
17. Tile a window with small hexagons.
18. Tile a window with small hexagons of different colour.
19. Define a class Poly that represents a polygon. Check if points constitute a polygon.
20. Define a class Star. One parameter should be number of points. Draw few stars with different number of points and colours.

Chapter 14

1. Drill: main features of OOP: interface & implementation inheritance ((abstract) base - derived classes), run - time polymorphism (virtual and pure virtual functions), encapsulation & data hiding (public, protected and private).
2. Define classes Smiley and Frowny, both derived from Circle, with members eyes and mouth. Next, derive classes from Smiley and Frowny which adds an appropriate hat to each.
3. Try to copy Shape. Comment the result.
4. Define an abstract class and then try to instantiate an object of that class. Comment the result.
5. Define a class Immobile_Circle that can't be moved.
6. Define a Striped_Rectangle where instead of fill the rectangle is "filled" with one-pixel-width lines. Play with line width and spacing.
7. Define a Striped_Circle using the technique from Striped_Rectangle.
8. Define a Striped_Polyline using the technique from Striped_Rectangle.
9. Define a class Octagon to be a regular octagon. Test all its functions.
10. Define Group to be a container of Shapes with suitable operations applied to the members of Group. Use Group to define a checkers board where piece can be moved under program control.
11. Define a Pseudo_window with rounded corners, label, control icons, fake contents such as image, within a Simple_window.
12. Define a Binary_tree class derived from Shape. Give the number of levels as parameter, depict nodes as circles.
13. Modify Binary_tree to draw its nodes using a virtual function. Derive a new class from Binary_tree that overrides the that virtual function to use different representation for a node (e.g. a triangle).
14. Add an operation to Binary_tree that adds text to node. Choose a way to identify a node (by a string of directions "lrlrl") for navigating left and right down a the tree (root is both l and r).
15. Define a class Iterator with pure virtual function next() that returns a pointer to double. Now derive Vector_iterator and List_iterator from Iterator so that next() for the first yields a pointer to the next element of a vector<double> and the latter one to list<double>. You initialize a Vector_iterator with vector<double> and the first call to next() yields a pointer to the first element, if any. If there is no next element, return 0. Test both by using a function void print (Iterator) to print the elements of vector and list of doubles.
16. Define class Controller with four virtual functions on(), off(), set_level(int) and show(). Derive at least two classes from Controller. One should be a simple test class where show() prints out whether the class is set on or off and what the current level is. The second class should control the line colour of Shape; the exact meaning of of "level" is up to you.
17. Draw a class hierarchy for the std::exception C++ standard library.

Chapter 15

1. Drill 1: Function graphing. Draw a coordinate system and functions.
2. Drill 2: Class definition. Define a class, const access members, overload extraction operator>> and insertion operators. Check validity of class instantiation data.
3. Implement an iterative factorial function. Compare it to recursive, comment complexity?
4. Define a class just like Function, but one that stores its constructor arguments and allows reset of their value.
5. Modify the the previous class and add new constructor argument that controls precision.
6. Plot sin(x), cos(x), their sum and the sum of their squares on a single graph. Provide labels.
7. Animate the Liebniz series: $1 - 1/3 + 1/5 - 1/7 + 1/9... = pi / 4$.
8. Design and implement a bar graph with basic data std::vector of double. Each value is represented by a "bar"'s height.
9. Modify the bar graph to allow labelling of individual bars and colour.
10. Here is a collection of (height[cm], frequency[people]) data points: (170, 7) (175, 9) (180, 23) (185, 17) (190, 6) (195, 1). Place them in a file, read and plot them. What would be the best graphical representation? Do a bar graph.
11. Find another data set of heights (in inches (1 inch = 2.54 cm)) and plot them with the code from the previous exercise. Scaling from the data is a key idea.
12. Find a way of displaying a collection of labelled points.
13. Read a data file containing mean maximum temperatures for each month of the year, for two locations and plot them together.

Chapter 16

1. Type the line - drawing program from §16.5 to §16.7.
2. Make My_window based on Window with two buttons next and quit.
3. Make a 4 x 4 Checkers board with four square buttons. When pressed, every button performs simple action: prints own coordinates, changes colour; till another button is pressed.
4. Define class with a Button that moves to a random position when pressed, together with an Image placed on it.
5. Make a menu with items that draws a circle, a square, an equilateral triangle, and a hexagon respectively. Make an input box for giving coordinate pair, and place the shape made by pressing a menu item at that coordinate.
6. Make a program that draws a shape of you choice and moves it to a new point each time you click "Next". The new point should be determined by a coordinate pair read from an input stream.
7. Make an "Analog Clock", that is, a clock with hands that move; get the time from OS library; find functions that wait for short period of time.
8. Make an image of an airplane "fly around" in a window. Have a "start" and "stop" button.
9. Provide a currency converter. Read the conversion rates from file on start-up. Enter amount in an input window and provide a way of selecting currencies to convert to and from (e.g. a pair of menus).
10. Modify the calculator from Chapter 7 to get its input from input box and to return its results to output box.
11. Provide a program where one can choose among a set of functions (e.g. sin(x), log(x)), provide parameters for those functions, and then graph them.

Chapter 17

1. Try This: apply sizeof() operator to the fundamental types and observe result. Analyse the behaviour of class constructors and destructors.
2. Drill: operator new and free-store allocations. Pointers, references and their properties.
3. What is the output format of a pointer value.
4. How many bytes are there in int, double, bool and other built-in types?
5. Write a function void to_lower(char \*s) that converts C-style string to lower case.
6. Write a function char\* strdup(char\*) that copies C-style string on free store.
7. Write a function char\* find(const char\* s, const char\* x), that finds first occurrence of the C-style string x in s.
8. Find a way to exhaust your machine's memory. Find what happens. Try using new or read documentation.
9. Read individual characters, until an exclamation mark (!) is entered, from std::cin into an array allocated on the free store.
10. Redo previous exercise using std::string instead of free store array.
11. Write a program that determines address order in heap, stack (and static) memory allocation.
12. Redo Exercise 7 (here 9) and use malloc() - free() and realloc() to extend the input char array.
13. Complete the "list of gods" from §17.10.1 and run it.
14. Why are there two different definitions of find() in the doubly linked list class?
15. Modify Link to hold a value struct God, with data members: std::string: name, mythology, vehicle and weapon. Write a print_all() and add_ordered() methods that places a new element in lexicographically right order. Make three list of Gods of different mythologies and then move them into ordered lists.

Chapter 18

1. Constructor (default, parameter, copy and assignment) and destructor calls.
2. Custom vector implementation, return by value and reading-only access.
3. Drill: arrays and vectors.
4. Write a function that copies a C-style string into free store memory and returns a pointer to it. Use dereference operator *, instead of subscripting operator[]; and no standard library functions.
5. Write a function that finds the first occurrence of a C-style string x in s; without any standard library functions and with the use of the dereference operator * instead of subscripting operator[].
6. Write a function that compares C-style string and returns negative value if first argument lexicographically before the second, positive value otherwise and 0 of they match.
7. Test the functions for non-zero terminated strings. Modify the functions to handle non-zero terminated strings.
8. Write a function, cat_dot(), that concatenated two strings with a dot in between.
9. Modify cat_dot() function to concatenate two strings, adding a separator in between, passed as third argument.
10. Rewrite cat_dot() for c-style strings as input parameters; let it return a c-string on the heap.
11. Rewrite all the functions from chapter §18.6 to check for palindrome by making a backward copy of the string and then comparing to the original.
12. Consider the memory layout in §17.3 (text, static, stack and heap). Write a program the shows memory addresses growth in each of the different types of memory.
13. Look at the "array solution" to the palindrome problem and fix it to handle: long strings by, either reporting for too long strings or allowing arbitrary long strings.
14. Look up and implement a skip list. (Not an easy exercise).
15. Implement a version of the game "Hunt the Wumpus". Make it work via the console.

Chapter 19

1. Try this 1: Consider problems in function resize(): "Out of range error" in vector element access.
2. Try this 2: add try-catch blocks in function suspicious() at all the places where resources are released.
3. Try this 3: modify function reserve() to use auto_ptr; compare solution to one where vector_base is used. Remark: impossible to implement using auto_ptr - no pointer arithmetic supported, can't access all elements.
4. Drill: exercises on templates<\>.
5. Write a template function that accumulates a std::vector of elements of an object of any type to which elements can be added.
6. Write a template function that takes two std::vectors as arguments and returns their inner product.
7. Write a template class Pair that can hold a pair of values of any type. Use this to implement a simple symbol table as the one used §7.8.
8. Modify class Link from §17.9.3 to be a template with the type of a value as the template argument. Redo Exercise 13 Chapter 17 with Link of God.
9. Define a class Int having a single member of type int. Define constructors, assignment, operators +, -, /, *, I/O operators <, operator >>.
10. Define a template class Number of T having a single member of any valid numeric type. Define constructors, assignment, operators+, -, /, \*, I/O operators <, operator >.
11. Redo Exercise 2, i.e. find the inner product of two vectors of using types Number of T.
12. Implement the allocator from §19.3.6 using malloc() and free(). Get the vector as defined by the end of §19.4 to work for a few simple test cases.
13. Re-implement vector::operator() (§19.2.5) using an allocator §19.3.6 for memory management.
14. Implement a simple auto_ptr supporting: constructor, destructor, operator->, \*, and release().
15. Design and implement a counted_ptr of T that is a type that holds a pointer to an object of type T and a pointer to a "use count (an int) shared by all counted pointers to the same object of type T. The use count should hold the number of counted pointers pointing to a given T.
16. Design and implement a file handler that takes a string argument (file name), opens the file in the constructor and closes it in the destructor.
17. Write a Tracer class where its constructor and destructor prints a string. Give the strings as constructor arguments. Experiment with Tracers as: local objects, global, objects allocated by new. Add copy constructor and copy assignment and observe where copying is done.
18. Provide a simple GUI interface output to the "Hunt the Wumpus" from Chapter 18. Take the input from an input box and display a map of the part of the cave currently known to the player in a window.
19. Modify the previous exercise to allow the user to mark rooms on the map based on knowledge and guesses, such as "maybe bats" and "bottomless pit".
20. Define a vector so sizeof( vector<int> )== sizeof( int * ), that is, the vector itself consists only of a pointer to a representation consisting of the elements, the number of elements, and the space pointer.

Chapter 20

1. Try this 1: modify the existing code and remove the ugliness.
2. Try this 2: remove errors from the modified code.
3. Try this 3: Write a function void copy (int* f1, int* e2, int* f2) that copies the elements of an array of ints defined by [f1, e1) into another [f2: f2 + (e1- f1)). Use only iterator operations and no subscript operator[].
4. Try this 4: find and remove the error in the code.
5. Try this 5: Implement push_front() for vector and compare it to push_back().
6. Try this 6: Modify the function advance() to accept negative argument.
7. Try this 7: For each array of char, vector of char, list of char, and string, define one with the value "Hello", pass it to a function as an argument, write out the number of characters in the string passed, try to compare it to "Hello", copy the argument into another variable of the same type.
8. Try this 8: Redo the previous Try This using containers of type int, initialized to { 1, 2, 3, 4, 5 }.
9. Drill: Use std::array, std::vector, std::list. Define copy() and std::find().
10. Do all the Try This exercises.
11. Get the "Jack and Jill" example from §20.1.2 to work. Use input from a couple of small files to test it.
12. Look the palindrome example from §18.6; redo the Jack and Jill example from §20.1.2 using that variety of techniques.
13. Find and fix errors in Jack and Jill in §20.3.1 by using STL techniques throughout.
14. Define <operator and >operator for std::vector.
15. Write find and replace function for class Document based on §20.6.2.
16. Find the lexicographically last string in an unsorted std::vector<std::string>.
17. Define a function that counts the number of characters in Document.
18. Define a function that counts the number of words in Document, where word is defined as: "white space separated sequence of characters" or "sequence of alphabetic characters".
19. Define a function that counts the number of words in Document, where the white space string is defined via function's argument.
20. Give a list std::list of int as a (by - reference) parameter, make a std::vector double and copy the elements of the list into it. Verify the copy was correct and complete. Print the elements sorted in increasing value.
21. Complete the definition of List from §20.4.1 - 2 and get high() example to run. Allocate a List to represent one past the end.
22. Modify the solution to the previous exercise to use 0 to represent the (non- existent) one-past-the-end Link (list<Elem> ::end()); that way the size of empty list is equal to the size of simple pointer.
23. Define a singly-linked list, slist, in the style of std::list. Which operations from List should be kept?
24. Define a pvector to be like vector of pointers except that it contains pointer to objects and its destructor deletes each object.
25. Define an ownership_vector that holds pointers to objects like pvector, but provides a mechanism for the user to decide which objects are owned by the vector (i.e., which objects are deleted by the destructor).
26. Define a range-checked iterator for vector (a random-access iterator).
27. Define a range-checked iterator for list (a bidirectional iterator).
28. Compare vector and list. Generate N random int numbers in the range [0, N). As each int is generated. insert it into a vector of int. Keep the vector sorted; that is, a value is inserted after every previous value that is less than or equal to the new value and before every value that is larger than the new value; do the same for the list. Explain result. (§26.6.1 explains how to time a program.)

Chapter 21

1. Try This 1: Write, test the functions find() and construct an argument for their being equivalent.
2. Try This 2: Why using implicit parameters could lead to obscure errors. List three examples where they should be avoided.
3. Try This 3: Define a std::vector of Record, initialize it with four Records of your choice, and compute their total price using the function in §21.5.2.
4. Try This 4: Write the example from §21.6.3 and get it to run.
5. Try This 5: Write a small program using #include <unordered_map>.
6. Try This 6: Get the program from §21.7.2 to run and test with small files of few hundred words. Try (the not recommended) guessing of the input size (potentially leading to buffer overflow).
7. Drill 1: algorithms with std::vector and std::list.
8. Drill 2: algorithms with std::map.
9. Drill 3: algorithms with std::vector<int> and std::vector<double>.
10. Do all Try this exercises (in case you haven't).
11. Find a reliable STL documentation and list every standard library algorithm.
12. Implement count() yourself. Test it.
13. Implement count_if() yourself. Test it.
14. Reimplement count() and count_if() as if there is no end() iterator.
15. Redo §21.6.5 but with std::set<Fruit*> instead. Provide a comparison operation Fruit_comparison, for std::set<Fruit*, Fruit_comparison>.
16. Implement a binary_search() function for std::vector and std::list. Test it. How much do they resemble each other?
17. Take the word frequency example from §21.6.1 and and modify it to to output its lines in order of frequency.
18. Define an Order class with (customer) name, address, data and vector of Purchase members. Purchase is a class with (product) name, unit prince, and count members. Define a mechanism for reading and writing to and from file. Define a mechanism for printing orders. Create a file of at least 10 orders, read it into a vector of Order, sort it by name (of customer), and write it back to file. Create another file of at least ten Orders, of which about the third are the same as in the first file, read into a list of Order, sort by address of customer and write back out to file. Merge the two files into third using std::merge();
19. Provide a GUI interface for entering Orders into files.
20. Provide a GUI interface for querying a file of Orders; e.g., "Find all orders from Joe," "Find the total value of orders in file Hardware," and "List all orders in file Clothing."
21. "Clean up" a text file for use in a word query program; that is, replace punctuation with white space, put words into lower case, replace "don't" with "do not" (etc.), and remove plurals (e.g., ships becomes ship).
22. Using the output from the previous exercise to answer questions such as: "How many occurrences of ship are there in a file?", "Which word occurs most frequently?", "Which is the longest word in the file?", "Which is the shortest?", "List all words starting with s.", "List all four-letter words."
23. Provide a GUI for the previous exercise.

Chapter 22

1. Define programming.
2. Define programming language.
3. Which of the chapter vignettes were written by a scientist? Write a paragraph with the contribution of each scientist.
4. Which of the chapter vignettes were written not by a scientist?
5. Write a "Hello, World!" program in each of the languages mentioned in this chapter.
6. For each language mentioned in this chapter, look at a popular textbook and see what is used as the first complete program. Write that program in all of the other languages. Warning: This could easily be a 100 - program project.
7. Make a list of five modern languages that you think ought to be covered and write a page and a half - along the lines of the languages sections in this chapter.
8. What is C++ used for and why? Write a 10- to 20- page report.
9. What is C used for and why? Write a 10- to 20-page report.
10. Pick one language (not C or C++) and write a 10- to 20-page description of its origins, aims, and facilities. Give plenty of concrete examples. Who uses it and for what?
11. Who currently holds the Lucasian Chair in Cambridge?
12. Of the language designers mentioned in this chapter, who has a degree in mathematics? Who does not?
13. Of the language designers mentioned in this chapter, who has a Ph.D.? In which field? Who does not have a Ph.D.?
14. Of the language designers mentioned in this chapter, who has received tlle Turing Award? What is that? Find the actual Turing Award citations for the winners mentioned here.
15. Write a program that, given a file of (name,year) pairs, such as (Algol,1960) and (C,1974), graphs the names on a timeline.
16. Modify the program from the previous exercise so that it reads a file of (name,year,(ancestors)) tuples, such as (Fortran,19S6,()), (Algol,1960,(Fortran), and (C++,198S,(C,Simula)), and graphs them on a timeline with arrows from ancestors to descendants. Use this program to draw improved versions of the diagrams in §22.2.2 and §22.2.7.

Chapter 23

1. Try this 1: What would be a better error handling? Modify Mail_file's constructor to handle likely formatting errors related to the use of "----" - (end of message indicator).
2. Try this 2: Write a brief explanation of the new terms used in the current section of the chapter.
3. Try this 3: Get the program from §23.8.7 to run and use it to try out some patterns, such as: abc, x.*x, (.*), \([^)]*\), \w+ \w+( Jr\.).
4. Drill: Find out if regex is shipped as part of your standard library. Try: std::regex and tr1::regex. Get the program from §23.7.7 to run. Install boost library; set project options; and include needed headers. Use the program to test the pattern from §23.7.
5. Exercise 1: Get the Mail_file example to run with file of your creation. Be sure to test with error-causing messages, such as: ones with two addresses, multiple messages with same addresses or same subject, and empty message. Test with file containing something that is not a message, such as a file containing only ....
6. Add a multimap and have it hold subjects. Let the program take an input string from the keyboard and print out every message with that string as its subject.
7. Modify the email example from §23.4 to use regular expressions to find the subject and sender.
8. Apply the previous program on real list of emails and extract the lines containing the subject.
9. Compare std::multimap against std::unordered_multimap, having in mind that the latter doesn't take advantage of ordering.
10. Write a program that finds dates in a file and displays the line containing the date and its number. Start with regular expression for simple formats like: 12/24/2017. Add more formats later.
11. Write a program that finds redit card numbers in a file and displays the line containing the date and its number.
12. Write a program that finds a pattern in a file and displays the line containing the pattern and its number.
13. Using eof() (§B.7.2), it is possible to determine which line of a table is the last. Use that to (try to) simplify the table-checking program from §23.9. Be sure to test your program with files that end with empty lines after the table and with files that don't end with a newline at all.
14. Modify the table-checking program from §23.9 to write a new table where the rows with the same initial digit are merged.
15. Modify the table-checking program from §23.9 to see if the number of students is increasing or decreasing over the years in question.
16. Write a program, based on the program that finds lines containing dates, that finds all dates and reformats them to the ISO yyyy/mm/dd format. The program should take an input file and produce an output file that is identical to the input file except for the changed date formatting.
17. Does dot (.) match '\n'? Write a program to find out.
18. Write a program similar to the one in §23.8.7, have it read a file into memory (representing a line break with the newline character, '\n'), so that you can experiment with patterns spanning line breaks. Test it and document a dozen test patterns.
19. Describe a pattern that cannot be expressed as a regular expression.
20. Prove that the pattern found in the previous exercise really isn't a regular expression.

Chapter 24

1. Try this 1: sum a the fraction 1/n n times and observe the result. Is it 1? Rounding Error.
2. Try this 2: Run the examples from §24.2 showing truncation, overflow and underflow examples due to intertype assignments, implicit conversion and algebraic calculations.
3. Drill 1: Print the size of a char, a short, an int, a long, a float, a double, an int*, and a double*. (use sizeof, not limits).
4. Drill 2: Print out the size as reported by sizeof of Matrix of int: a(10), Matrix of int: b(10), Matrix of double: c(10), 2D Matrix of int: d(10,10), 3D Matrix of int: e(10, 10, 10).
5. Drill 3: Print out the elements of the matrices from the previous exercise.
6. Drill 4: Write a program that takes ints from d n and outputs the sqrt() of each int, or "no square root" if sqrt(x) is illegal for some x (i.e., check your sqrt() return values).
7. Drill 5: Read ten floating-point values from input and put them into a Matrix of double. Matrix has no push_back() so be careful to handle an attempt to enter a wrong number of doubles. Print out the Matrix.
8. Drill 6: Compute a multiplication table for [O, n) x [O,m) and represent it as a 2D Matrix. Take n and m from std::cin and print out the table nicely (assume that m is small enough that the results fit on a line).
9. Drill 7: Read ten complex of doubles from std::cin and put them into a Matrix. Calculate and output the sum of the ten complex numbers.
10. Drill 8: Read six ints into a 2D Matrix of int, m(2, 3) and print them out.
11. The function arguments f for a.apply(f) and apply(f,a) are different. Write a double() function for each and use each to double the elements of an array { 1, 2, 3, 4, 5 }. Define a single double() function that can be used for both a.apply(double) and apply(double, a). Explain why it could be a bad idea to write every function to be used by apply() that way.
12. Do, the previous, Exercise 1 again, but with function objects, rather than functions.
13. Write an apply(f,a) that can takes a void f(T&), a T f(const T&), and their function object equivalents. Hint: Boost::bind.
14. Get the Gaussian elimination program to work; that is, complete it, get it to compile, and test it with a simple example.
15. Try the Gaussian elimination program with A={ {O 1} {1 O} } and b={ 5 6 } and watch it fail. Then, try elim_with_partiat_pivot().
16. In the Gaussian elimination example, replace the vector operations dot_product() and scale_and_add() with loops. Test, and comment on the clarity of the code.
17. Rewrite the Gaussian elimination program without using the Matrix library; that is, use built-in arrays or vectors instead of Matrices.
18. Animate the Gaussian Elimination.
19. Rewrite the non-member apply() functions to return a Matrix of the return type of the function applied that is, apply(f, a) should return a Matrix of type R where R is the return type of f. Warning: The solution requires information about templates not available in this book.
20. How random is your rand()? Write a program that takes two integers n and d as inputs and calls randint(n) d times, recording the result. Output the number of draws for each of [0 : n) and "eyeball" how similar tile counts are. Try with low values for n and with low values for d to see if drawing only a few random numbers causes obvious biases.
21. Write a swap_columns() to match swap_rows() from §24.S.3. Obviously, to do that you have to read and understand some of the existing Matrix library code. Don't worry too much about efficiency: it is not possible to get swap_columns() to run as fast as swap_rows().
22. Implement: Matrix operator multiplication (2DMatrix&, 1DMatrix&);, i.e. tensor-vector dot product and Matrix operator+ (Matrix&, Matrix&); for randomly multidimensional matrices.

Chapter 25

1. Try This 1: Replace 333 in the example with 10 and run the example again. What result would you expect? What result did you get?
2. Тry This 2: Before reading further, try to see how many errors you can find in f() in §25.4.3. Specifically, which of the calls of poor() could cause the program to crash?
3. Try This 3: Get the bits example to work and try out a few values to develop a feel for binary and hexadecimal representations. If you get confused about the representation of negative values, just try again after reading §25.5.3.
4. Try This 4: Inspect the loop in §25.5.3 with signed char as loop variable and unsigned char as termination variable. Why it's infinite?
5. Try This 5: Draw out the bit patterns on a piece or paper. Using paper, then figure out what the answer would be for si = 128 in §25.5.3. Then run the program to see if your machine agrees.
6. Drill 1: Bit shifting and multiplication.
7. Drill 2: Unsigned short Bit manipulations.
8. Exercise 1: Do Try This Exercise.
9. Hexspeak.
10. Integer bit patterns.
11. Add the bitwise logical operators &, |, ^ , and ~ to the calculator from Chapter 7.
12. Write an infinite loop. Execute it.
13. Write an infinite loop that is hard to recognize as an infinite loop. A loop that isn't really infinite because it terminates after completely consuming some resource is acceptable.
14. Write out the hexadecimal values from 0 to 400; and from -200 to 200.
15. Write out the numerical values of each character on your keyboard.
16. Without using any standard headers (such as limits or documentation, compute the number of bits in an int and determine whether char is signed or unsigned on your implementation.
17. Look at the bitfield example from §25.5.5. Write an example that initializes a PPN, then reads and prints each field value, then changes each field value (by assigning the field), and prints the result. Repeat this exercise, but store the PPN information in a 32-bit unsigned integer and use bit manipulation operators (§25.5.4) to access the bits in the word.
18. Redo previous exercise using bitset.
19. Write out the clear text of the example from §25.5.6.
20. Implement a simple vector that can hold at most N elements allocated from a pool. Test it for N == 1000 and integer elements.
21. Measure the time it takes to de / allocate 10000 objects of random sizes in [10000:0) - byte range. Do this twice: once deallocate in reverse order and once deallocate in random order.
22. Formulate 20 coding style rules (don't just copy those in §25.6). Apply them to a program of more than 300 lines that you recently wrote.
23. Proof that Array_ref handles inheritance correctly by trying to get a Rectangle\* into std::vector<Circle\*> using Array_ref<Shape\*>, without using casts or other operations involving undefined behaviour.

Chapter 26

1. Implement a Binary Search algorithm by yourself. How do you know it is correct?
2. Drill 1: Implement the input operator for Test from §26.3.2.2.
3. Drill 2: Complete a file of tests for the sequences from §26.3: empty sequence, single element, odd and even number, equal elements, different elements at end.
4. Drill 3: Based on §26.3.2.3, complete a program that generates (ordered): a very large sequence, ten sequences with random number of elements, ten sequences with elements: 0,1,2,...,9 random elements.
5. Drill 4: Repeat these tests for sequences of strings, such as: { Bohr Darwin Einstein Lavoisier Newton Turing }.
6. Exercise 1: Run your binary search algorithm from §26.1 wilt the tests presented in §26.3.2.1.
7. Modify the testing of binary_search() to deal with arbitrary element types. Then, test it with std::string sequences and float sequences.
8. Repeat the exercise in §26.2.1 with the version of binary_search that takes a comparison criterion. Make a list of new opportunities for errors introduced by that extra argument.
9. Devise a format for test data so that you can define a sequence once and run several tests against.
10. Add a test to the set of binary_search tests to try to catch the (unlikely) error of a binary_search modifying the sequence.
11. Modify the calculator from Chapter 7 minimally to let it take input from a file and produce output to a file (or use your operating system's facilities for redirecting I/O ). Then devise a reasonably comprehensive test for it.
12. Test the "simple text editor" from §20.6.
13. Add a text-based interface to the graphics interface library from Chapters 12 - 15. For example, the string: "Circle(Point(O, 1), 15)" should generate a call Circle(Point(O, 1), 15). Use this text interface to make a "kid 's drawing" of a two-dimensional house with a roof, two windows, and a door.
14. Add a text-based output format for the graphics interface library. For example, when a call Circle(Point(0,1),15) is executed, a string like: "Circle(Point(0,1),15)" should be produced on an output stream.
15. Use the text-based interface from Exercise 9 to write a better test for the graphical interface library.
16. Time the sum example from §26.6 with m being square matrices with dimensions 100, 10.000, 1.000.000, and 10.000.000. Use random element values in the range [-10: 10). Rewrite the calculation of v to use a more efficient (not O(n^2)) algorithm and compare the timings.
17. Write a program that generates random floating-point numbers and sorts them using std::sort. Measure the time used to sort 500,000 doubles and 5,000,000 doubles.
18. Write a program that generates random length, within [0,100), std::strings and sorts them using std::sort. Measure the time used to sort 500,000 and 5,000,000 strings.
19. Repeat the previous exercise, except using a std::map rather than a std::vector so that we don't need to sort.

Chapter 27

1. Try This 1: Test cat(). Why 2? We left a beginner's performance error in cat(); find it and remove it. We "forgot" to comment our code. Add comments suitable for someone who can be assumed to know the standard C - string functions.
2. Is this implementation of strcpy() correct? Explain why.
3. Rewrite the intrusive list example in C++, showing how to make it shorter and easier to use without making the code slower or the objects bigger.
4. Drill 1: Write a "Hello, World!" program in C, compile it, and run it.
5. Define two variables holding "Hello" and "World!" respectively; concatenate them with a space in between; and output them as Hello, World!.
6. Define a C function that takes a char* parameter p and an int parameter x and prints out their values in this format: p is "foo" and x is 7. Call it with a few argument pairs.
7. Exercise 1: Implement versions of strlen(), strcmp(), and strcpy().
8. Complete the intrusive list example in §27.9 and test it using every function.
9. "Pretty up" the intrusive list example in §27.9 as best you can to make it convenient to use. Do catch / handle as many error's as you can. It is fair game to change the details of the struct definitions, to use macros, whatever.
10. If you didn't already, write a C++ version of the intrusive list example in §27.9 and test it using every function.
11. Compare the results of Exercises 3 and 4.
12. Change the representation of Link and List from §27.9 without changing the user interface provided by the functions. Allocate Links in an array of Links and have the members: first, last, prev, and next be ints (indices into the array).
13. What are the advantages and disadvantages of intrusive containers compared to C++ standard (non-intrusive) containers? Make lists of pros and cons.
14. What is the lexicographical order on your machine? Write out every character on your keyboard together with its integer value; then, write the characters out in the order determined by their integer value.
15. Using only C facilities, including the C standard library, read a sequence of words from stdin and write them to stdout in lexicographical order. Hint: The C sort function is called qsort(); look it up somewhere. Alternatively, insert the words into an ordered list as you read them. There is no C standard library list.
16. Make a list of C language features adopted from C++ or C with Classes (§27.1).
17. Make a list of C language features not adopted by C++.
18. Implement a (C-style string, int) lookup table with operations such as find (struct table*, const char*), insert (struct table*, const char*, int), and remove (struct table*, const char*). The representation of the table could be an array of a struct pair or a pair of arrays (const char* [] and int*); you choose. Also choose return types for your functions. Document your design decisions.
19. Write a program that does the equivalent of string s; cin >> s; in C; that is, define an input operation that reads an arbitrarily long sequence of white space - terminated characters into a zero - terminated array of chars.
20. Write a function that takes an array of ints as its input and finds the smallest and the largest elements; It should also compute the median and mean. Use a struct holding the results as the return value.
21. Simulate single inheritance in C. Let each "base class" contain a pointer to an array of pointers to functions (to simulate virtual functions as free standing functions taking a pointer to a "base class" object as their first argument); see §27.2.3. Implement "derivation" by making the "base class" the type of the first member of the derived class. For each class, initialize the array of "virtual functions" appropriately. To test the ideas, implement a version of "the old Shape example" with the base and derived draw() just printing out the name of their class. Use only language features and library facilities available in standard C.
22. Use macros to obscure (simplify the notation for) the implementation in the previous exercise.

===

Additional dependencies:

For the first few chapters:

http://www.stroustrup.com/Programming/std_lib_facilities.h

For chapters 12 - 15, in some exercises in chapters 21, 22, 26:

http://www.stroustrup.com/Programming/FLTK/

For chapter 24:

http://www.stroustrup.com/Programming/Matrix/

Files structure and code style:

Each file starts with:

/*
    TITLE          [brief_title]       	         [file_name.extension]
    Book name and author.
    COMMENT
        Objective: [exercise intent]
            Input: [expected]
           Output: [expected]
           Author: [name]
             Date: [date of last modification]
*/

For the sake of clarity braces ,{ }, are on a new line:

int main() 
{

    // Code
        // indentation
            // is
                // 4
                    // spaces.
        
}

Names of variables and functions start with lower case and contain upper case or underscore "_", in case of complex names; classes and namespaces start with upper case. Example:

namespace MyExample 
{

    int var;

    int func (int par);
    
    int res_var;
    
    class ObjectOriented
    {
    
    };

}

File organization:

1.Main (Execution) files, FileName.cpp, contain the included compiler libraries
and custom libraries, followed by the main() function;
Global variables are avoided.

2.Header files, FileName.h contain guards using the file name in upper case:

#ifnded FILE_NAME_H
#define FILE_NAME_H

// declarations

#include "FileNameDef.cpp"
#endif

3.Implementation files FileNameDef.cpp contain class/function implementations,
separated either by:

----------------------------

or

===========================

with comments before the body of definition:

/*
    Function:
    Use:
    
    Description
*/

Files naming convention:

Chapter[number]TryThis[number].cpp

Chapter[number]Drill[number].cpp

Chapter[number]Exercise[number].cpp

Chapter[number]Exercise[number].h

Chapter[number]Exercise[number]Def.cpp

---

OS: Windows 7, Windows 10
IDE: Visual Studio 2010, CodeBlocks

---

MIT License

Copyright (c) 2017 Chris B. Kirov

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

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