Answers to Selected Exercises for Programming and Problem Solving With C++

154 Pages·2004·0.649 MB·English

by  Nell B. Dale, Chip Weems

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Answers to
Selected Exercises
Chapter 1 Exam Preparation Exercises
1. a.v, b.i, c.viii, d.iii, e.iv, f.vii, g.vi, h.ii.
2. Analysis and specification, general solution (algorithm), verify.
3. Concrete solution (program), test.
4. The analysis and specification step within the problem-solving phase.
5. The steps never end. Changing the last step to say, “Repeat from first step until gradua-
tion,” converts the sequence into an algorithm that eventually ends, assuming the person
will graduate from school some day. We can make sure that this loop ends by specifying
a condition that will definitely occur. For example, “Repeat from first step until last day
of classes.”
6. a.vi, b.ii, c. v, d.i, e.vii, f.iv.
7. The program can be compiled on different computer systems without modification.
8. The control unit directs the actions of the other components in the computer to execute
program instruction in the proper order.
9. False. The editor is software rather than hardware.
10. False. Peripheral devices are external to the CPU and its main memory.
11. Yes. If the software license restricts use to a single computer or a single user, then this is
a case of piracy, even though you split the cost.
12. a.ii, b.v, c. iii, d.vii, e.i, f.vi, g.iv.
Chapter 1 Programming Warm-Up Exercises
1. Branches: Steps n1, n2, and n3. There are two loops: steps p, q, and r; and steps t and u.
Steps a, c, and e are references to subalgorithms defined elsewhere.
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2. follow separate algorithm for filling glass with water and placing on counter
If right-handed,
pick up toothpaste tube in left hand and unscrew cap by turning counter-clockwise
place toothpaste cap on counter
transfer toothpaste tube to right hand and pick up toothbrush in left hand, holding it by its
handle
place open end of toothpaste tube against tips of brush bristles and squeeze toothpaste tube
just enough to create a 0.5-inch-long extrusion of toothpaste on brush
pull toothpaste tube away from brush and place tube on counter
transfer toothbrush to right hand, holding it by its handle
open mouth and insert brush, placing toothpaste-covered bristles against one tooth
scrub tooth with brush by moving brush up and down 10 times
reposition brush to an unscrubbed tooth
repeat previous two steps until all teeth have been brushed
spit toothpaste into sink
put toothbrush in sink
pick up glass in right hand
fill mouth with water from glass
swish water in mouth for five seconds
spit water from mouth into sink
repeat previous three steps three times
Otherwise (if left-handed)
pick up toothpaste tube in right hand and unscrew cap by turning counter-clockwise
place toothpaste cap on counter
transfer toothpaste tube to left hand and pick up toothbrush in right hand, holding it by its
handle
place open end of toothpaste tube against tips of brush bristles and squeeze toothpaste tube
just enough to create a 0.5-inch-long extrusion of toothpaste on brush
pull toothpaste tube away from brush and place tube on counter
transfer toothbrush to left hand, holding it by its handle
open mouth and insert brush, placing toothpaste-covered bristles against one tooth
scrub tooth with brush by moving brush up and down 10 times
reposition brush to an unscrubbed tooth
repeat previous two steps until all teeth have been brushed
spit toothpaste into sink
put toothbrush in sink
pick up glass in left hand
fill mouth with water from glass
swish water in mouth for five seconds
spit water from mouth into sink
repeat previous three steps three times
Place glass on counter
Follow separate algorithm for cleaning up after brushing teeth
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3. The test for right- or left-handedness is a branch. Each branch contains two loops, one
that iterates until all teeth are brushed and another that iterates rinsing four times. The
first and last steps refer to separately defined subalgorithms.
4. Change step u to:
u. Repeat step t nine times.
Chapter 1 Case Study Follow-Up Exercises
1. a. 1900 No
b. 2000 Yes
c. 1996 Yes
d. 1998 No
2. a. 1900 Line = 6
b. 1945 Line = 2
c. 1600 Line = 7
d. 1492 Line = 4
e. 1776 Line = 4
3. Divide by 1000 and see if the remainder is 0.
4. I was not, but your answer may be different.
5. Keep adding 1 to the year and test it until you find the next leap year. Another algo-
rithm would be to use the following:
nextYear = year + (year % 4)
divide the nextYear by 100 and if the remainder isn’t 0,
Write that nextYear is the next leap year
Otherwise, divide the nextYear by 400 and if the remainder isn’t 0
Write that (nextYear + 4) is the next leap year
Otherwise nextYear is the next leap year
6. Line Number
{
__1___ if (year % 4 != 0)
__2___ return false;
__3___ else if (year % 100 != 0)
__4___ return true;
__5___ else if (year % 400 != 0)
__6___ return false;
__7___ else return true;
}
Chapter 2 Exam Preparation Exercises
1. a. valid, b. invalid (hyphens not allowed), c. invalid (reserved words not allowed), d.valid,
e.valid, f.valid, g.invalid (must begin with a letter), h. invalid (# is not allowed).
2. a.vi, b.ix, c.iv, d.v, e.vii,f. ii, g.i, h.x, i.iii, j.viii.
3. False.
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4. The template allows an identifier to begin with a digit. Identifiers can begin with a letter
or an underscore, and digits may appear only in the second character position and
beyond.
5. False.
6. True.
7. True.
8. Note that the second line concatenates two words without a separating space.
Four score and
seven years agoour fathers
brought forth on this
continent a new nation...
9. ”Bjarne Stroustrup named his new programming language C++ because it is a successor
to the C programming language.”
10. By preceding it with a backslash character (\”).
11. If we forget the */ at the end of a comment, then any number of lines of program code
can be inadvertently included in the comment. The // form avoids this by automatically
terminating at the end of the line.
12. The // form of comment cannot span more than one line. It also cannot be inserted into
the middle of a line of code because everything to the right of //becomes a comment.
13. <<is the stream insertion operator, and is pronounced “put to” or “is sent,” as in “cout is
sent string4.”
14. No. The endlidentifier is a manipulator, and is not a string value.
15. It tells the C++ preprocessor to insert the contents of a specified file at that point in the
code.
16. std::cout << "Hello everybody!" << std::endl;
17. A block.
18. By splitting it into pieces that fit on a line, and joining them with the concatenation
operator.
19. #include <iostream>
#include <string>
using namespace std;
const string TITLE = "Dr.";
int main()
{
cout << "Hello " + TITLE + " Stroustrup!";
}
Chapter 2 Programming Warm-Up Exercises
1. Substitute the actual data in the following:
cout << "July 4, 2004" << endl;
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2. Note that the \"escape sequence is needed in six places here:
cout << "He said, \"How is that possible?\"" << endl
<< "She replied, \"Using manipulators.\"" << endl
<< "\"Of course,\" he exclaimed!" << endl;
3. a. const string ANSWER = "True";
b. char middleInitial;
c. string courseTitle;
d. const char PERCENT = '%'
4. const string FIRST = "Your first name inserted here";
const string LAST = "Your last name inserted here";
// Insert your middle initial in place of A:
const char MIDDLE = 'A';
5. cout << PART1 << PART2 << PART1 << PART3;
6. PART1 + PART2 + PART1 + PART3
7. cout << "Yet the web of thought has no such creases"
<< endl;
cout << "And is more like a weaver's masterpieces;"
<< endl;
cout << "One step a thousand threads arise," << endl;
cout << "Hither and thither shoots each shuttle," << endl;
cout << "The threads flow on unseen and subtle," << endl;
cout << "Each blow effects a thousand ties." << endl;
8. #include <iostream>
#include <string>
using namespace std;
const string TITLE = "Rev.";
const char FIRST = 'H';
const char MID 'G';
const char DOT = '.';
int main()
{
cout << TITLE << FIRST << DOT << MID << DOT
<< " Jones";
}
9. The solution to this problem is for the student to show that he or she has run the pro-
gram correctly. It should output:
***********************************
* *
* Welcome to C++ Programming! *
* *
***********************************
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Chapter 2 Case Study Follow-Up
1. const string BLACK = "%%%%%%%%"; // Define a line of a black square
2. const string WHITE = "........"; // Define a line of a white square
3. Move the first five output statements to the end of the program.
4.
const string BLACK = "**********"; // Define a line of a black square
const string WHITE = " "; // Define a line of a white square
5.
//******************************************************************
// Chessboard program
// This program prints a chessboard pattern that is built up from
// basic strings of white and black characters.
//******************************************************************
#include <iostream>
#include <string>
using namespace std;
const string BLACK = "********"; // Define a line of a black square
const string WHITE = " "; // Define a line of a white square
const string BLACK_BLANK = "** **"; // Define a constant of embedded
// blanks
int main ()
{
string whiteRow; // A row beginning with a white square
string blackRow; // A row beginning with a black square
string blackBlankRow; // A black first row with mixed squares
string whiteBlankRow; // A white first row with mixed squares
// Create a white-black row by concatenating the basic strings
whiteRow = WHITE + BLACK + WHITE + BLACK +
WHITE + BLACK + WHITE + BLACK;
// Create a white-black row with interior blanks in the blacks
whiteBlankRow = WHITE + BLACK_BLANK + WHITE + BLACK_BLANK +
WHITE + BLACK_BLANK + WHITE + BLACK_BLANK;
// Create a black-white row with interior blanks in the blacks
blackBlankRow = BLACK_BLANK + WHITE + BLACK_BLANK + WHITE +
BLACK_BLANK + WHITE + BLACK_BLANK + WHITE;
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// Create a black-white row by concatenating the basic strings
blackRow = BLACK + WHITE + BLACK + WHITE +
BLACK + WHITE + BLACK + WHITE;
// Print five white-black rows
cout << whiteRow << endl;
cout << whiteRow << endl;
cout << whiteBlankRow << endl;
cout << whiteBlankRow << endl;
cout << whiteRow << endl;
// Print five black-white rows
cout << blackRow << endl;
cout << blackRow << endl;
cout << blackBlankRow << endl;
cout << blackBlankRow << endl;
cout << blackRow << endl;
// Print five white-black rows
cout << whiteRow << endl;
cout << whiteRow << endl;
cout << whiteBlankRow << endl;
cout << whiteBlankRow << endl;
cout << whiteRow << endl;
// Print five black-white rows
cout << blackRow << endl;
cout << blackRow << endl;
cout << blackBlankRow << endl;
cout << blackBlankRow << endl;
cout << blackRow << endl;
// Print five white-black rows
cout << whiteRow << endl;
cout << whiteRow << endl;
cout << whiteBlankRow << endl;
cout << whiteBlankRow << endl;
cout << whiteRow << endl;
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// Print five black-white rows
cout << blackRow << endl;
cout << blackRow << endl;
cout << blackBlankRow << endl;
cout << blackBlankRow << endl;
cout << blackRow << endl;
// Print five white-black rows
cout << whiteRow << endl;
cout << whiteRow << endl;
cout << whiteBlankRow << endl;
cout << whiteBlankRow << endl;
cout << whiteRow << endl;
// Print five black-white rows
cout << blackRow << endl;
cout << blackRow << endl;
cout << blackBlankRow << endl;
cout << blackBlankRow << endl;
cout << blackRow << endl;
return 0;
}
6. There are 64 characters per line, except for the results of Exercise 4, which would have
80 characters per line.
Chapter 3 Exam Preparation Exercises
1. They are simple data types.
2. char, short, int, long.
3. Integer overflow.
4. E signifies an exponent in scientific notation. The digits to the left of the E are multiplied
by 10 raised to the power given by the digits to the right of the E.
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5.
integer / constant /
floating variable
a. const int TRACKS_ON_DISK = 17; integer constant
b. float timeOfTrack; floating variable
c. const float MAX_TIME_ON_DISK = 74.0; floating constant
d. short tracksLeft; integer variable
e. float timeLeft; floating variable
f. long samplesInTrack; integer variable
g. const double SAMPLE_RATE = 262144.5; floating constant
6. Integer division with an integer result, and floating division with a floating result.
7. a.21, b.21.6, c.13.0, d.18, e. 20, f. 22, g.18.0.
8. () unary - [ * / % ] [ + - ]
9. True.
10. a. vi, b.ii, c. vii, d. iv, e. i, f.v, g.iii.
11. The ++operator.
12. You write the name of a data type, followed by an expression enclosed in parentheses.
13. mainreturns an intvalue.
14. 215.00
15. False. When used alone they are equivalent, but used within a larger expression, they can
give different results (this is explained more in Chapter 10).
16. string::size_type
17. a. 29
b. 1
c. "ought to start with logic"
d. 0
e. "log"
f. 1
g. string::npos
18. It tells the stream to print floating-point numbers without using scientific notation.
Chapter 3 Programming Warm-Up Exercises
1. (hours * 60 + minutes) * 60 + seconds
2. a. days / 7
b. days % 7
3. dollars * 100 + quarters * 25 + dimes *10 + nickels * 5 + pennies
4. float(dollars * 100 + quarters * 25 + dimes *10 +
nickels * 5 + pennies) / 100.0
5. count = count + 3;
6. a. 3 * X + Y
b. A * A + 2 * B + C
c. ((A + B)/(C – D)) * (X / Y)
d. ((A * A + 2 * B + C)/D) / (X * Y)
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e. sqrt(fabs(A – B))
f. pow(X, -cos(Y))
7. string temp;
temp = sentence;
first = temp.find("and"); // Get first location
// Remove first section of string
temp = temp.substr(first + 3, temp.length() – (first + 3));
// Find second location of "and" in shortened string
second = temp.find("and");
// Remove next section of string
temp = temp.substr(second + 3, temp.length() – (second + 3));
// Adjust second to account for deleting first part of string
second = second + first + 3;
// Locate third "and" and adjust for prior deletions
third = temp.find("and") + second + 3;
8. startOfMiddle = name.find(' ') + 1;
9. cout << "$" << fixed << setprecision(2) << setw(8) << money;
10. cout << setprecision(5) << setw(15) << distance;
11. #include <climits>
cout << "INT_MAX = " << INT_MAX << " INT_MIN = " << INT_MIN;
12. //**********************************************
// Celsius program
// This program outputs the Celsius temperature
// corresponding to a given Fahrenheit temperature
//**********************************************
#include <iostream>
using namespace std;
int main()
{
const float FAHRENHEIT = 72.0;