The Modern C# Challenge: Become an expert C# programmer by solving interesting programming problem

Cover....1

Title Page....2

Copyright and Credits....3

Dedication....4

Packt Upsell....5

Contributors....6

Table of Contents....8

Preface....14

Chapter 1: Mathematics....20

Problems....20

1. Statistical functions....20

2. Permutations....22

3. Combinations....23

4. Factorials....24

5. Fibonacci numbers....24

6. Binomial coefficients....25

7. Pascal's triangle....26

8. Greatest common divisors....26

9. Least common multiples....26

10. Sums of multiples....27

11. Primality testing....27

12. Prime table....27

13. Prime factors....27

14. Unique prime factors....28

15. Prime tuples....28

16. Proper divisors....28

17. Amicable numbers....29

18. Perfect numbers....29

19. Armstrong numbers....29

Solutions....29

1. Statistical functions....30

2. Permutations....35

3. Combinations....39

4. Factorials....41

5. Fibonacci numbers....43

6. Binomial coefficients....48

7. Pascal's triangle....52

8. Greatest common divisors....56

9. Least common multiples....58

10. Sums of multiples....59

11. Primality testing....63

12. Prime table....64

13. Prime factors....68

14. Unique prime factors....71

15. Prime tuples....73

16. Proper divisors....75

17. Amicable numbers....77

18. Perfect numbers....79

19. Armstrong numbers....80

Chapter 2: Geometry....82

Problems....82

20. Monte Carlo π....82

21. Newton's π....83

22. Bisection root-finding....83

23. Newton's method....84

24. Gaussian elimination....85

25. Monte Carlo integration....89

26. Rectangle rule integration....90

27. Trapezoid rule integration....91

28. Arrowheads....92

29. Line-line intersection....93

30. Point-line distance....93

31. Point-segment distance....94

32. Segment-segment distance....94

33. Circle selection....94

34. Line-circle intersection....95

35. Circle-circle intersection....95

36. Circle-line tangents....95

37. Polygon area....96

38. Point in a polygon....96

39. Convexity testing....96

40. Stars....96

Solutions....97

20. Monte Carlo π....98

21. Newton's π....101

22. Bisection root-finding....102

23. Newton's method....105

24. Gaussian elimination....106

25. Monte Carlo integration....112

26. Rectangle rule integration....114

27. Trapezoid rule integration....116

28. Arrowheads....118

29. Line-line intersection....123

30. Point-line distance....127

31. Point-segment distance....128

32. Segment-segment distance....129

33. Circle selection....132

34. Line-circle intersection....134

35. Circle-circle intersection....137

36. Circle-line tangents....141

37. Polygon area....143

38. Point in a polygon....145

39. Convexity testing....148

40. Stars....150

Chapter 3: Dates and Times....152

Problems....152

41. Days of the week....152

42. Date and time picker....152

43. Time zone chart....153

44. Scheduling meetings....153

45. Time zone clocks....153

46. Local time zone clocks....154

47. Calculating duration....155

48. Calculating age....155

Solutions....155

41. Days of the week....155

42. Date and time picker....157

43. Time zone chart....159

44. Scheduling meetings....164

45. Time zone clocks....164

46. Local time zone clocks....166

47. Calculating duration....167

48. Calculating age....168

Chapter 4: Randomization....171

Problems....171

49. Random doubles....171

50. Random items....171

51. Randomize items....172

52. Random groups....172

53. Choose items with probabilities....172

54. Random passwords....172

55. Random walks....173

Solutions....173

49. Random doubles....173

50. Random items....174

51. Randomize items....175

52. Random groups....176

53. Choose items with probabilities....178

54. Random passwords....178

55. Random walks....180

Chapter 5: Strings....182

Problems....182

56. Roman numerals....182

57. Bytes to hex....183

58. Removing punctuation....183

59. Palindromic substrings....183

60. Validating passwords....184

61. Edit distance....184

62. Soundex....185

63. Longest common substring....186

Solutions....187

56. Roman numerals....187

57. Bytes to hex....191

58. Removing punctuation....192

59. Palindromic substrings....193

60. Validating passwords....196

61. Edit distance....197

62. Soundex....204

63. Longest common substring....205

Chapter 6: Files and Directories....211

Problems....211

64. Removing blank lines....211

65. Directory size....212

66. Finding duplicate files....212

67. Thumbnails....212

68. Thumbnail web page....213

69. Find files....213

70. Find and Replace....213

71. Saving images....214

72. Compressing images....214

Solutions....214

64. Removing blank lines....214

65. Directory size....215

66. Finding duplicate files....217

67. Thumbnails....221

68. Thumbnail web page....225

69. Find files....227

70. Find and Replace....229

71. Saving images....231

72. Compressing images....233

Chapter 7: Advanced C# and .NET Features....235

Problems....235

73. Directory size, LINQ style....236

74. Directory size, PLINQ style....236

75. Find files, LINQ style....236

76. Parallel primes table....236

77. Parallel prime tuples....236

78. Parallel Monte Carlo π....236

79. Yielding primes....237

80. Yielding Fibonacci numbers....237

81. Complex numbers....237

Solutions....238

73. Directory size, LINQ style....238

74. Directory size, PLINQ style....239

75. Find files, LINQ style....241

76. Parallel primes table....242

77. Parallel primes tuple....247

78. Parallel Monte Carlo π....252

79. Yielding primes....255

80. Yielding Fibonacci numbers....256

81. Complex numbers....257

Chapter 8: Simulations....269

Problems....270

82. Dawkins' weasel....270

83. Hailstone sequence....271

84. Hailstone sequence, Redux....272

85. Langton's Ant....273

86. Life....274

87. Sharks and Fish....275

88. Slingshot....276

89. Slingshot refinements....278

90. Space Force....279

Solutions....279

82. Dawkins' weasel....280

83. Hailstone sequence....283

84. Hailstone Sequence, Redux....286

85. Langton's Ant....288

86. Life....291

87. Sharks and Fish....294

88. Slingshot....296

Projectile motion....297

Example solution....297

89. Slingshot refinements....300

90. Space Force....303

Sprite classes....303

Bubble....306

Ship....307

Keyboard events....310

Other details....312

Chapter 9: Cryptography....313

Problems....314

91. Caesar cipher....314

92. Vigenère cipher....314

93. Cryptographic pseudorandom numbers....315

94. Primality testing, redux....316

95. Find primes....318

96. Hash files....318

97. Steganography....319

98. Encrypt and decrypt strings....319

99. Encrypt and decrypt files....320

100. CryptoPad....321

Solutions....321

91. Caesar cipher....321

92. Vigenère cipher....324

93. Cryptographic random numbers....324

94. Primality testing, redux....329

95. Find primes....331

96. Hash files....332

97. Steganography....333

98. Encrypt and decrypt strings....338

99. Encrypt and decrypt files....343

100. CryptoPad....345

Other Books You May Enjoy....350

Index....353

Learn advanced C# concepts and techniques such as building caches, cryptography, and parallel programming by solving interesting programming challenges

Key Features

• Gain useful insights on advanced C# programming topics and APIs
• Use locking and cached values to solve parallel problems
• Take advantage of .NET's cryptographic tools to encrypt and decrypt strings

Book Description

C# is a multi-paradigm programming language. The Modern C# Challenge covers with aspects of the .NET Framework such as the Task Parallel Library (TPL) and CryptoAPI. It also encourages you to explore important programming trade-offs such as time versus space or simplicity. There may be many ways to solve a problem and there is often no single right way, but some solutions are definitely better than others. This book has combined these solutions to help you solve real-world problems with C#.

In addition to describing programming trade-offs, The Modern C# Challenge will help you build a useful toolkit of techniques such as value caching, statistical analysis, and geometric algorithms.

By the end of this book, you will have walked through challenges in C# and explored the .NET Framework in order to develop program logic for real-world applications.

What you will learn

• Perform statistical calculations such as finding the standard deviation
• Find combinations and permutations
• Search directories for files matching patterns using LINQ and PLINQ
• Find areas of polygons using geometric operations
• Randomize arrays and lists with extension methods
• Explore the filesystem to find duplicate files
• Simulate complex systems and implement equality in a class
• Use cryptographic techniques to encrypt and decrypt strings and files

Who this book is for

The Modern C# Challenge is for all C# developers of different abilities wanting to solve real-world problems. There are problems for everyone at any level of expertise in C#