Category:Racket

1

• 100 doors

2

• 24 game
• 24 game/Solve

9

• 9 billion names of God the integer
• 99 Bottles of Beer

A

• A+B
• Abstract type
• Accumulator factory
• Ackermann function
• Active Directory/Connect
• Active object
• Addition-chain exponentiation
• Address of a variable
• Align columns
• Amb
• Anagrams
• Animate a pendulum
• Animation
• Anonymous recursion
• Apply a callback to an array
• Arbitrary-precision integers (included)
• Arithmetic evaluation
• Arithmetic-geometric mean
• Arithmetic/Complex
• Arithmetic/Integer
• Arithmetic/Rational
• Array concatenation
• Arrays
• Assertions
• Associative array/Creation
• Associative array/Iteration
• Averages/Arithmetic mean
• Averages/Mean angle
• Averages/Median
• Averages/Mode
• Averages/Pythagorean means
• Averages/Root mean square
• Averages/Simple moving average

B

• Balanced brackets
• Benford's law
• Best shuffle
• Binary digits
• Binary search
• Binary strings
• Bitmap
• Bitmap/Flood fill
• Bitwise operations
• Boids simulation
• Boolean values
• Box the compass
• Bulls and cows

C

• Caesar cipher
• Call a foreign-language function
• Call a function
• Call a function in a shared library
• Call an object method
• Case-sensitivity of identifiers
• Casting out nines
• Catalan numbers
• Catalan numbers/Pascal's triangle
• Catamorphism
• Character codes
• Character matching
• Chat server
• Check input device is a terminal
• Check output device is a terminal
• Check that file exists
• Checkpoint synchronization
• Cholesky decomposition
• Classes
• Closest-pair problem
• Closures/Value capture
• Collections
• Color quantization
• Colour bars/Display
• Colour pinstripe/Display
• Colour pinstripe/Printer
• Combinations
• Combinations and permutations
• Combinations with repetitions
• Command-line arguments
• Comments
• Compile-time calculation
• Compound data type
• Concurrent computing
• Conditional structures
• Conjugate transpose
• Constrained random points on a circle
• Continued fraction
• Convert decimal number to rational
• Conway's Game of Life
• Copy a string
• Count in factors
• Count in octal
• Count occurrences of a substring
• Count the coins
• CRC-32
• Create a file
• Create a file on magnetic tape
• Create a two-dimensional array at runtime
• Create an HTML table
• CSV to HTML translation
• Currying

D

• Date format
• Date manipulation
• Day of the week
• Death Star
• Deepcopy
• Define a primitive data type
• Delete a file
• Detect division by zero
• Determine if a string is numeric
• Determine if only one instance is running
• Digital root
• Dijkstra's algorithm
• Dinesman's multiple-dwelling problem
• Dining philosophers
• DNS query
• Documentation
• Dot product
• Doubly-linked list/Definition
• Doubly-linked list/Element definition
• Doubly-linked list/Element insertion
• Doubly-linked list/Traversal
• Dragon curve
• Draw a clock
• Draw a cuboid
• Draw a sphere
• Dutch national flag problem
• Dynamic variable names

E

• Echo server
• Empty directory
• Empty program
• Empty string
• Enforced immutability
• Entropy
• Entropy/Narcissist
• Enumerations
• Environment variables
• Equilibrium index
• Ethiopian multiplication
• Euler method
• Evaluate binomial coefficients
• Even or odd
• Evolutionary algorithm
• Exceptions
• Exceptions/Catch an exception thrown in a nested call
• Executable library
• Execute a Markov algorithm
• Execute a system command
• Execute Brain****
• Exponentiation operator
• Extend your language
• Extreme floating point values

F

• Factorial
• Factors of a Mersenne number
• Factors of an integer
• Fast Fourier transform
• Fibonacci n-step number sequences
• Fibonacci sequence
• File IO
• File modification time
• File size
• Filter
• Find common directory path
• Find first and last set bit of a long integer
• Find largest left truncatable prime in a given base
• Find last sunday of each month
• Find limit of recursion
• Find the missing permutation
• First class environments
• First-class functions
• First-class functions/Use numbers analogously
• Five weekends
• FizzBuzz
• Flatten a list
• Flow-control structures
• Floyd's triangle
• Forest fire
• Fork
• Formal power series
• Formatted numeric output
• Forward difference
• Four bit adder
• Fractal tree
• Function composition
• Function definition
• Function frequency
• Function prototype

G

• Game of Nim
• Gamma function
• Gaussian elimination
• Generator/Exponential
• Generic swap
• Globally replace text in several files
• Go Fish
• Gray code
• Greatest common divisor

G cont.

• Greatest element of a list
• Greatest subsequential sum
• Greyscale bars/Display
• Guess the number
• Guess the number/With feedback
• Guess the number/With feedback (player)
• GUI component interaction
• GUI enabling/disabling of controls
• GUI/Maximum window dimensions

H

• Hailstone sequence
• Hamming numbers
• Handle a signal
• Happy numbers
• Harshad or Niven series
• Hash from two arrays
• Haversine formula
• Hello world/Graphical
• Hello world/Line printer
• Hello world/Newline omission
• Hello world/Standard error
• Hello world/Text
• Hello world/Web server
• Here document
• Higher-order functions
• History variables
• Hofstadter Q sequence
• Holidays related to Easter
• Honeycombs
• Horizontal sundial calculations
• Horner's rule for polynomial evaluation
• Host introspection
• Hostname
• HTTP
• HTTPS
• HTTPS/Authenticated
• HTTPS/Client-authenticated
• Huffman coding

I

• Identity matrix
• Include a file
• Increment a numerical string
• Infinity
• Inheritance/Multiple
• Inheritance/Single
• Input loop
• Integer comparison
• Integer sequence
• Interactive programming
• Introspection
• Inverted syntax

J

• Jensen's Device
• Josephus problem
• JSON
• Jump anywhere

K

• K-means++ clustering
• Kaprekar numbers
• Keyboard input/Flush the keyboard buffer
• Keyboard input/Keypress check
• Keyboard input/Obtain a Y or N response
• Keyboard macros
• Knapsack problem/0-1
• Knuth shuffle
• Knuth's algorithm S

L

• Langton's ant
• Largest int from concatenated ints
• Last Friday of each month
• Last letter-first letter
• Leap year
• Least common multiple
• Letter frequency
• Levenshtein distance
• Levenshtein distance/Alignment
• Linear congruential generator
• List comprehensions
• Literals/Floating point
• Literals/Integer
• Literals/String
• Logical operations
• Long multiplication
• Longest common subsequence
• Longest string challenge
• Look-and-say sequence
• Loop over multiple arrays simultaneously
• Loops/Break
• Loops/Continue
• Loops/Do-while
• Loops/Downward for
• Loops/For
• Loops/For with a specified step
• Loops/Foreach
• Loops/Infinite
• Loops/N plus one half
• Loops/Nested
• Loops/While
• LU decomposition
• Lucas-Lehmer test
• Luhn test of credit card numbers
• LZW compression

M

• Mad Libs
• Make a backup file
• Man or boy test
• Mandelbrot set
• Map range
• Matrix arithmetic
• Matrix multiplication
• Matrix transposition
• Matrix-exponentiation operator
• Maze generation
• Maze solving
• MD4
• MD5
• MD5/Implementation
• Memory allocation
• Memory layout of a data structure
• Menu
• Metaprogramming
• Metered concurrency
• Metronome
• Middle three digits
• Miller-Rabin primality test
• Modular exponentiation
• Modular inverse
• Monte Carlo methods
• Monty Hall problem
• Mouse position
• Multifactorial
• Multiline shebang
• Multiple distinct objects
• Multiple regression
• Multiplication tables
• Multiplicative order
• Multisplit
• Munching squares
• Mutex
• Mutual recursion

N

• N-queens problem
• Named parameters
• Narcissist
• Non-decimal radices/Convert
• Non-decimal radices/Input
• Non-decimal radices/Output
• Nth root
• Null object
• Number names
• Number reversal game
• Numerical integration
• Numerical integration/Gauss-Legendre Quadrature

O

• Odd word problem
• One of n lines in a file
• One-dimensional cellular automata
• OpenGL
• Operator precedence
• Optional parameters
• Order two numerical lists
• Ordered Partitions
• Ordered words

P

• Palindrome detection
• Pangram checker
• Parallel calculations
• Parametric polymorphism
• Parse command-line arguments
• Parsing/RPN calculator algorithm
• Parsing/RPN to infix conversion
• Partial function application
• Pascal's triangle
• Pattern matching
• Percentage difference between images
• Perfect numbers
• Permutations
• Permutations by swapping
• Permutations/Derangements
• Pi
• Pick random element
• Pig the dice game
• Pig the dice game/Player
• Pinstripe/Display
• Pinstripe/Printer
• Playing cards
• Plot coordinate pairs
• Pointers and references
• Polynomial regression
• Power set
• Pragmatic directives
• Price fraction
• Primality by trial division
• Prime decomposition
• Priority queue
• Probabilistic choice
• Problem of Apollonius
• Program name
• Program termination
• Pythagorean triples

Q

• QR decomposition
• Quaternion type
• Queue/Definition
• Queue/Usage
• Quine

R

• Random number generator (device)
• Random number generator (included)

R cont.

• Random numbers
• Range expansion
• Range extraction
• Rate counter
• Ray-casting algorithm
• Read a configuration file
• Read a file character by character/UTF8
• Read a file line by line
• Read a specific line from a file
• Read entire file
• Real constants and functions
• Reduced row echelon form
• Regular expressions
• Remove duplicate elements
• Remove lines from a file
• Rename a file
• Rep-string
• Repeat a string
• Return multiple values
• Reverse a string
• RIPEMD-160
• Rock-paper-scissors
• Roman numerals/Decode
• Roman numerals/Encode
• Roots of a function
• Roots of a quadratic function
• Roots of unity
• Rosetta Code/Count examples
• Rosetta Code/Find unimplemented tasks
• Rosetta Code/Fix code tags
• Rosetta Code/Rank languages by popularity
• Rot-13
• Run-length encoding
• Runge-Kutta method
• Runtime evaluation
• Runtime evaluation/In an environment

S

• S-Expressions
• Safe addition
• Same Fringe
• Scope modifiers
• Scripted main
• Search a list
• Secure temporary file
• SEDOLs
• Self-describing numbers
• Semordnilap
• Send email
• Sequence of non-squares
• Set
• Set consolidation
• Set of real numbers
• Set puzzle
• Seven-sided dice from five-sided dice
• SHA-1
• SHA-256
• Shell one-liner
• Short-circuit evaluation
• Show the epoch
• Sierpinski carpet
• Sierpinski triangle
• Sierpinski triangle/Graphical
• Sieve of Eratosthenes
• Simple windowed application
• Simulate input/Keyboard
• Singleton
• Singly-linked list/Element definition
• Singly-linked list/Element insertion
• Singly-linked list/Traversal
• Sleep
• Sockets
• Sort an array of composite structures
• Sort an integer array
• Sort disjoint sublist
• Sort stability
• Sort using a custom comparator
• Sorting algorithms/Bead sort
• Sorting algorithms/Bogosort
• Sorting algorithms/Bubble sort
• Sorting algorithms/Counting sort
• Sorting algorithms/Insertion sort
• Sorting algorithms/Merge sort
• Sorting algorithms/Permutation sort
• Sorting algorithms/Quicksort
• Sorting algorithms/Selection sort
• Sorting algorithms/Sleep sort
• Sorting algorithms/Stooge sort
• Sorting algorithms/Strand sort
• Soundex
• Special characters
• Special variables
• Spiral matrix
• Stable marriage problem
• Stack
• Stack traces
• Stair-climbing puzzle
• Standard deviation
• Start from a main routine
• Statistics/Normal distribution
• Stem-and-leaf plot
• String case
• String comparison
• String concatenation
• String interpolation (included)
• String length
• Strip a set of characters from a string
• Strip block comments
• Strip comments from a string
• Strip control codes and extended characters from a string
• Strip whitespace from a string/Top and tail
• Substring
• Substring/Top and tail
• Subtractive generator
• Sudoku
• Suffix tree
• Sum and product of an array
• Sum digits of an integer
• Sum multiples of 3 and 5
• Sum of a series
• Sum of squares
• Symmetric difference
• Synchronous concurrency
• System time

T

• Table creation/Postal addresses
• Take notes on the command line
• Temperature conversion
• Terminal control/Clear the screen
• Terminal control/Coloured text
• Terminal control/Cursor movement
• Terminal control/Cursor positioning
• Terminal control/Dimensions
• Terminal control/Display an extended character
• Terminal control/Hiding the cursor
• Terminal control/Inverse video
• Terminal control/Positional read
• Terminal control/Preserve screen
• Terminal control/Ringing the terminal bell
• Terminal control/Unicode output
• Ternary logic
• Test a function
• Text processing/1
• Text processing/2
• Text processing/Max licenses in use
• Tic-tac-toe
• Time a function
• Tokenize a string
• Top rank per group
• Topic variable
• Topological sort
• Topswops
• Towers of Hanoi
• Trabb Pardo–Knuth algorithm
• Tree traversal
• Trigonometric functions
• Truncatable primes
• Truncate a file
• Truth table
• Twelve statements

U

• Unbias a random generator
• Undefined values
• Unicode strings
• Unicode variable names
• Universal Turing machine
• Update a configuration file
• URL decoding
• URL encoding
• User input/Graphical
• User input/Text

V

• Vampire number
• Van der Corput sequence
• Variable-length quantity
• Variables
• Variadic function
• Vector products
• Verify distribution uniformity/Chi-squared test
• Verify distribution uniformity/Naive
• Vigenère cipher
• Vigenère cipher/Cryptanalysis
• Visualize a tree
• Voronoi diagram

W

• Walk a directory/Non-recursively
• Walk a directory/Recursively
• Web scraping
• Window creation
• Window creation/X11
• Window management
• Word wrap
• Write float arrays to a text file
• Write language name in 3D ASCII
• Write to Windows event log

X

• XML/Input
• XML/Output

Y

• Y combinator
• Yin and yang

Z

• Zebra puzzle
• Zeckendorf number representation
• Zig-zag matrix