# Reports:Tasks not implemented in Racket

**Awareness**

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## Contents

## Not implemented[edit]

These are currently not implemented in Racket. Please implement some if you can. If any tasks are not possible or too complex in Racket, they should not be on this list. To mark a task as such, add **{{omit from|Racket}}**, preserving the capitalization of the language, to that task. It will appear below under the "Not Considered" section.

### A

### C

- Calkin-Wilf sequence
- Canny edge detector
- Canonicalize CIDR
- Catmull–Clark subdivision surface
- Chaocipher
- Chernick's Carmichael numbers
- Circular primes
- Cistercian numerals
- Compare length of two strings
- Compare sorting algorithms' performance
- Compiler/AST interpreter
- Compiler/code generator
- Compiler/syntax analyzer
- Compiler/virtual machine interpreter
- Consecutive primes with ascending or descending differences
- Cyclotomic polynomial

### E

### F

### I

### L

- Lah numbers
- Largest number divisible by its digits
- Largest proper divisor of n
- Latin Squares in reduced form
- Latin Squares in reduced form/Randomizing using Jacobson and Matthews’ Technique
- Law of cosines - triples
- Legendre prime counting function
- Long literals, with continuations
- Long year
- Loops/With multiple ranges
- Lucky and even lucky numbers

### M

- Magic squares of doubly even order
- Magic squares of singly even order
- Magnanimous numbers
- Mastermind
- Mayan calendar
- Mayan numerals
- Merge and aggregate datasets
- Mertens function
- Metallic ratios
- Mian-Chowla sequence
- Mind boggling card trick
- Minimal steps down to 1
- Minimum positive multiple in base 10 using only 0 and 1
- Minkowski question-mark function
- Modified random distribution
- Monads/Writer monad
- Motzkin numbers
- Möbius function

### N

### P

- P-Adic numbers, basic
- P-Adic square roots
- P-value correction
- Padovan n-step number sequences
- Padovan sequence
- Palindrome dates
- Palindromic gapful numbers
- Pancake numbers
- Peaceful chess queen armies
- Pell's equation
- Peripheral drift illusion
- Pierpont primes
- Pisano period
- Playfair cipher
- Primality by Wilson's theorem
- Pseudo-random numbers/Combined recursive generator MRG32k3a
- Pseudo-random numbers/Middle-square method
- Pseudo-random numbers/PCG32
- Pseudo-random numbers/Splitmix64
- Pseudo-random numbers/Xorshift star

### R

### S

- SHA-256 Merkle tree
- SOAP
- Safe primes and unsafe primes
- Self numbers
- Sequence: nth number with exactly n divisors
- Sequence: smallest number greater than previous term with exactly n divisors
- Sequence: smallest number with exactly n divisors
- Set right-adjacent bits
- Sexy primes
- Sierpinski arrowhead curve
- Sierpinski square curve
- Sleeping Beauty problem
- Smarandache prime-digital sequence
- Snake
- Sort an outline at every level
- Sorting algorithms/Cocktail sort with shifting bounds
- Spelling of ordinal numbers
- Square form factorization
- Stirling numbers of the first kind
- Stirling numbers of the second kind
- Strassen's algorithm
- Strong and weak primes
- Successive prime differences
- Suffixation of decimal numbers
- Sum of elements below main diagonal of matrix
- Summarize primes
- Super-d numbers
- Sylvester's sequence

### T

### Draft tasks without implementation[edit]

These tasks are drafts, meaning they largely need more work to turn them into full tasks. Perhaps you can help by trying to implement them in Racket (after all, one of the key requirements for a task being non-draft is multiple implementations, preferably in widely different languages) but be aware that this may be difficult because of lack of definition of the task itself.

### A

### B

### C

- CLI-based maze-game
- Camel case and snake case
- Change e letters to i in words
- Changeable words
- Checksumcolor
- Chess player
- Code Golf: Code Golf
- Collect and sort square numbers in ascending order from three lists
- Combinations with repetitions/Square digit chain
- Common list elements
- Common sorted list
- Compiler/Simple file inclusion pre processor
- Compiler/Verifying syntax
- Composite numbers k with no single digit factors whose factors are all substrings of k
- Concatenate two primes is also prime
- Conjugate a Latin verb
- Continued fraction/Arithmetic/G(matrix ng, continued fraction n1, continued fraction n2)
- Coprime triplets
- Count how many vowels and consonants occur in a string
- Count the coins/0-1
- Cousin primes
- Create your own text control codes
- Cubic Special Primes
- Cullen and Woodall numbers
- Curve that touches three points
- Cyclops numbers

### D

- Data Encryption Standard
- Dating agency
- Day of the week of Christmas and New Year
- Days between dates
- Digit fifth powers
- Diophantine linear system solving
- Discrete Fourier transform
- Distinct Palindromes within decimal numbers
- Distinct power numbers
- Distribution of 0 Digits in factorial series
- Divide a rectangle into a number of unequal triangles
- Dominoes
- Doomsday rule
- Doubly-linked list/Element removal

### E

### F

- Fibonacci heap
- Fibonacci matrix-exponentiation
- Find adjacent primes which differ by a square integer
- Find first missing positive
- Find minimum number of coins that make a given value
- Find prime n such that reversed n is also prime
- Find prime numbers of the form n*n*n+2
- Find square difference
- Find squares n where n+1 is prime
- Find words which contains all the vowels
- First 9 Prime Fibonacci Number
- Frobenius numbers

### G

### L

- Largest difference between adjacent primes
- Largest five adjacent number
- Largest palindrome product
- Largest prime factor
- Largest product in a grid
- Last list item
- Length of an arc between two angles
- Line circle intersection
- Logistic curve fitting in epidemiology
- Long stairs
- Longest common suffix
- Longest palindromic substrings
- Longest substrings without repeating characters

### M

- Magic constant
- Maximum difference between adjacent elements of list
- Mersenne primes
- Minimum multiple of m where digital sum equals m
- Minimum number of cells after, before, above and below NxN squares
- Minimum numbers of three lists
- Minimum primes
- Multi-base primes
- Multidimensional Newton-Raphson method
- Multiton

### N

- N-body problem
- Neighbour primes
- Next special primes
- Nice primes
- Number triplets game
- Numbers divisible by their individual digits, but not by the product of their digits.
- Numbers in base-16 representation that cannot be written with decimal digits
- Numbers in base 10 that are palindromic in bases 2, 4, and 16
- Numbers which are not the sum of distinct squares
- Numbers which binary and ternary digit sum are prime
- Numbers whose count of divisors is prime
- Numbers with prime digits whose sum is 13
- Numbers with same digit set in base 10 and base 16
- Numerical integration/Adaptive Simpson's method

### O

### P

- Palindromic primes
- Palindromic primes in base 16
- Pandigital prime
- Parse EBNF
- Particle fountain
- Permutations with some identical elements
- Permuted multiples
- Piprimes
- Polynomial derivative
- Positive decimal integers with the digit 1 occurring exactly twice
- Powerful numbers
- Practical numbers
- Price list behind API
- Prime numbers p which sum of prime numbers less or equal to p is prime
- Prime numbers which contain 123
- Prime triplets
- Prime words
- Primes which contain only one odd digit
- Primes whose first and last number is 3
- Primes whose sum of digits is 25
- Primes with digits in nondecreasing order
- Print itself
- Process SMIL directives in XML data
- Product of divisors
- Pseudorandom number generator image

### R

- Ramanujan primes
- Range modifications
- Raster bars
- Recursive descent parser generator
- Remote agent/Agent interface
- Remote agent/Agent logic
- Remote agent/Simulation
- Remove vowels from a string
- Repunit primes
- Resistance calculator
- Resistance network calculator
- Reverse the order of lines in a text file while preserving the contents of each line
- Robots
- Rodrigues’ rotation formula
- Rosetta Code/List authors of task descriptions
- Rosetta Code/Run examples
- Rosetta Code/Tasks without examples
- Round-robin tournament schedule
- Ruth-Aaron numbers

### S

- Safe and Sophie Germain primes
- Safe mode
- Sanitize user input
- Segmentation fault protection
- Self-hosting compiler
- Shift list elements to left by 3
- Show the (decimal) value of a number of 1s appended with a 3, then squared
- Sierpinski curve
- Simple turtle graphics
- Smallest enclosing circle problem
- Smallest multiple
- Smallest number k such that k+2^m is composite for all m less than k
- Smallest numbers
- Smallest power of 6 whose decimal expansion contains n
- Smallest square that begins with n
- Solve a Rubik's Cube
- Solve equations with substitution method
- Solving coin problems
- Sort primes from list to a list
- Sort the letters of string in alphabetical order
- Special Divisors
- Special factorials
- Special neighbor primes
- Special pythagorean triplet
- Spoof game
- Steady Squares
- Strange numbers
- Strange plus numbers
- Strange unique prime triplets
- Substring primes
- Sum data type
- Sum of first n cubes
- Sum of primes in odd positions is prime
- Sum of square and cube digits of an integer are primes
- Sum of the digits of n is substring of n
- Sum of two adjacent numbers are primes
- Summation of primes

### T

### U

### V

### W

## Requiring Attention[edit]

### Examples[edit]

These tasks have implementations in Racket, but somebody, somewhere, decided that the example implementation was faulty or in some other way requiring attention. If you're familiar with the task and language, please consider reviewing/correcting the example and removing the notice.

### Other pages[edit]

These are other pages related to Racket which require attention; with your knowledge and assistance, we can improve the quality of the site's content.

### No pages found.

## Not Considered[edit]

These tasks are not generally counted toward "unimplemented", as somebody, somewhere, decided that Racket was inappropriate for these tasks, or implementations of them would be unenlightening. Feel free to try your hand at them anyway.

### No pages found.

## End of List[edit]

Again, feel free to try your hand at any of the tasks listed on this page.