Programming Abstractions in C++

This text is intended for use in the second programming course

Programming is a matter of learning by doing. Eric Roberts’ Programming Abstractions in C++ gives students opportunities to practice and learn with engaging graphical assignments. A client-first approach to data structures helps students absorb, and then apply the material.

Teaching and Learning Experience

This program presents a better teaching and learning experience—for you and your students. It will help:

• Improve Student Comprehension with a Client-first Approach to Data Structures: To aid in student understanding, this book presents the full set of collection classes early.
• Defer the Presentation of C++ Features that Require a Detailed Understanding of the Underlying Machine: Introducing collection classes early enables students to master other equally important topics without having to struggle with low-level details at the same time.
• Engage Students with Exciting Graphical Assignments: An open-source library supports graphics and interactivity in a simple, pedagogically appropriate way.
• Support Instructors and Students: The companion website provides source code, sample run PDFs, answers to review questions, and more.

This program presents a better teaching and learning experience for you and your students. It will help:

• Improve Student Comprehension with a Client-first Approach to Data Structures: To aid in student understanding, this book presents the full set of collection classes early.
• Defer the Presentation of C++ Features that Require a Detailed Understanding of the Underlying Machine: Introducing collection classes early enables students to master other equally important topics without having to struggle with low-level details at the same time.
• Engage Students with Exciting Graphical Assignments: An open-source library supports graphics and interactivity in a simple, pedagogically appropriate way.
• Support Instructors and Students: The companion website provides source code, sample run PDFs, answers to review questions, and more.

MARKET: This text is intended for use in the second programming course.

After receiving his Ph.D. in Applied Mathematics from Harvard University in 1980, Eric Roberts taught at Wellesley College from 1980-85, where he chaired the Computer Science Department. From 1985-90, he was a member of the research staff at Digital Equipment Corporation’s Systems Research Center in Palo Alto, California, where he conducted computer science research, focusing on programming tools for multiprocessor architectures. In September 1990, Roberts joined the Stanford faculty, where he is now Professor of Computer Science and the John A. and Cynthia Fry Gunn University Fellow in Undergraduate Education.

From 1990 to 2002, Professor Roberts was Associate Chair and Director of Undergraduate Studies for Computer Science. In that capacity, he was the principal architect of Stanford’s introductory programming sequence, which for many years held the distinction of being the largest course at Stanford. He has also written four computer science textbooks that are used at many colleges and universities throughout the world. His research focuses on computer science education, particularly for underserved communities. From 1998 to 2005, Roberts was Principal Investigator for the Bermuda Project, which developed the computer science curriculum for Bermuda’s public secondary schools.

While at Stanford, Professor Roberts has received several university- level teaching awards, including the Bing Fellowship, established “to recognize excellence in teaching and a committed interest to the teaching of undergraduates”; the Dinkelspiel Award, which recognizes “distinctive and exceptional contributions to undergraduate education”; and the Laurance and Naomi Carpenter Hoagland Prize, awarded for excellence in undergraduate teaching. In January 2002, Roberts was named one of the first eight University Fellows in Undergraduate Education, which are designed “to reward faculty who make truly outstanding contributions to Stanford’s undergraduate experience.”

Professor Roberts has been active in professional organizations dedicated to computer science education. From 2005 to 2007, he served as co-chair of the Education Board of the Association of Computing Machinery (ACM) and was for many years on the board of the ACM Special Interest Group on Computer Science Education (SIGCSE). From 1998 to 2001, Roberts served as co-chair and principal editor for the ACM/IEEE- CS Joint Task Force on Computing Curricula 2001, which published a detailed set of curriculum guidelines in December 2001. He also chaired the ACM Java Task Force from 2004 to 2006. In 2003, Roberts received the SIGCSE Award for Outstanding Contribution to Computer Science Education. Professor Roberts is a Fellow of the ACM and the American Association for the Advancement of Science (AAAS).

Professor Roberts has also been active in several organizations seeking to promote socially responsible use of science and technology. He is past president of both Computer Professionals for Social Responsibility, a public-interest organization of computer scientists and other professionals concerned about the impact of computer technology on society, and Student Pugwash USA, which encourages students to use their training in science and technology to create a better world. In 1999-2000, Roberts was the Eugene M. Lang Visiting Professor for Social Change at Swarthmore College.

1 Overview of C++ 1

1.1 Your first C++ program 2

1.2 The history of C++ 3

1.3 The structure of a C++ program 6

1.4 Variables 14

1.5 Data types 19

1.6 Expressions 26

1.7 Statements 36

Summary 47

Review questions 48

Exercises 50

2 Functions and Libraries 55

2.1 The idea of a function 56

2.2 Libraries 59

2.3 Defining functions in C++ 61

2.4 The mechanics of function calls 65

2.5 Reference parameters 73

2.6 Interfaces and implementations 78

2.7 Principles of interface design 85

2.8 Designing a random number library 90

2.9 Introduction to the Stanford libraries 107

Summary 112

Review questions 114

Exercises 115

3 Strings 125

3.1 Using strings as abstract values 126

3.2 String operations 129

3.3 The library 137

3.4 Modifying the contents of a string 138

3.5 The legacy of C-style strings 139

3.6 Writing string applications 140

3.7 The strlib.h library 146

Summary 147

Review questions 148

Exercises 149

4 Streams 159

4.1 Using strings as abstract values 160

4.2 Formatted input 165

4.3 Data files 167

4.4 Class hierarchies 181

4.5 The simpio.h and filelib.h libraries 186

Summary 188

Review questions 189

Exercises 190

5 Collections 195

5.1 The Vector class 197

5.2 The Stack class 211

5.3 The Queue class 217

5.4 The Map class 226

5.5 The Set class 232

5.6 Iterating over a collection 236

Summary 243

Review questions 245

Exercises 246

6 Designing Classes 261

6.1 Representing points 262

6.2 Operator overloading 268

6.3 Rational numbers 281

6.4 Designing a token scanner class 292

6.5 Encapsulating programs as classes 301

Summary 303

Review questions 305

Exercises 306

7 Introduction to Recursion 315

7.1 A simple example of recursion 316

7.2 The factorial function 318

7.3 The Fibonacci function 325

7.4 Checking palindromes 332

7.5 The binary search algorithm 335

7.6 Mutual recursion 336

7.7 Thinking recursively 338

Summary 340

Review questions 342

Exercises 344

8 Recursive Strategies 349

8.1 The Towers of Hanoi 350

8.2 The subset-sum problem 361

8.3 Generating permutations 364

8.4 Graphical recursion 368

Summary 375

Review questions 375

Exercises 376

9 Backtracking Algorithms 389

9.1 Recursive backtracking in a maze 390

9.2 Backtracking and games 400

9.3 The minimax algorithm 409

Summary 415

Review questions 416

Exercises 417

10 Algorithmic Analysis 429

10.1 The sorting problem 430

10.2 Computational complexity 435

10.3 Recursion to the rescue 443

10.4 Standard complexity classes 449

10.5 The Quicksort algorithm 452

10.6 Mathematical induction 458

Summary 462

Review questions 463

Exercises 466

11 Pointers and Arrays 473

11.1 The structure of memory 474

11.2 Pointers 484

11.3 Arrays 494

11.4 Pointer arithmetic 500

Summary 506

Review questions 508

Exercises 510

12 Dynamic Memory Management 515

12.1 Dynamic allocation and the heap 516

12.2 Linked lists 519

12.3 Freeing memory 523

12.4 Defining a CharStack class 527

12.5 Heap-stack diagrams 536

12.6 Unit testing 543

12.7 Copying objects 546

12.8 The uses of const 550

12.9 Efficiency of the CharStack class 558

Summary 560

Review questions 562

Exercises 564

13 Efficiency and Representation 569

13.1 Software patterns for editing text 570

13.2 Designing a simple text editor 572

13.3 An array-based implementation 579

13.4 A stack-based implementation 586

13.5 A list-based implementation 591

Summary 607

Review questions 608

Exercises 610

14 Linear Structures 615

14.1 Templates 616

14.2 Implementing stacks 619

14.3 Implementing queues 634

14.4 Implementing vectors 649

14.5 Integrating prototypes and code 656

Summary 657

Review questions 658

Exercises 659

15 Maps 663

15.1 Implementing maps using vectors 664

15.2 Lookup tables 668

15.3 Hashing 671

15.4 Implementing the HashMap class 682

Summary 683

Review questions 684

Exercises 685

16 Trees 689

16.1 Family trees 691

16.2 Binary search trees 693

16.3 Balanced trees 706

16.4 Implementing maps using BSTs 717

16.5 Partially ordered trees 719

Summary 722

Review questions 724

Exercises 727

17 Sets 737

17.1 Sets as a mathematical abstraction 738

17.2 Expanding the set interface 742

17.3 Implementation strategies for sets 747

17.4 Optimizing sets of small integers 753

Summary 761

Review questions 762

Exercises 764

18 Graphs 767

18.1 The structure of a graph 768

18.2 Representation strategies 772

18.3 A low-level graph abstraction 776

18.4 Graph traversals 783

18.5 Defining a Graph class 789

18.6 Finding shortest paths 804

18.7 Algorithms for searching the web 808

Summary 812

Review questions 813

Exercises 815

19 Inheritance 823

19.1 Simple inheritance 824

19.2 A hierarchy of graphical shapes 832

19.3 A class hierarchy for expressions 841

19.4 Parsing an expression 861

19.5 Multiple inheritance 870

Summary 873

Review questions 875

Exercises 877

20 Strategies for iteration 885

20.1 Using iterators 886

20.2 Using functions as data values 890

20.3 Encapsulating data with functions 899

20.4 The STL algorithms library 904

20.5 Functional programming in C++ 907

20.6 Implementing iterators 911

Summary 918

Review questions 920

Exercises 921

A Stanford library interfaces 927

Index 1025