# Reports:Tasks not implemented in Quackery

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## Contents

## Not implemented[edit]

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

### A

- AKS test for primes
- ASCII art diagram converter
- AVL tree
- Abbreviations, automatic
- Abbreviations, easy
- Abbreviations, simple
- Abelian sandpile model
- Abelian sandpile model/Identity
- Abstract type
- Accumulator factory
- Active Directory/Connect
- Active Directory/Search for a user
- Active object
- Add a variable to a class instance at runtime
- Address of a variable
- Align columns
- Aliquot sequence classifications
- Almost prime
- Amb
- Angles (geometric), normalization and conversion
- Animate a pendulum
- Animation
- Append a record to the end of a text file
- Apply a digital filter (direct form II transposed)
- Approximate equality
- Archimedean spiral
- Arena storage pool
- Arithmetic-geometric mean/Calculate Pi
- Arithmetic/Complex
- Arithmetic evaluation
- Assertions
- Associative array/Creation
- Associative array/Iteration
- Associative array/Merging
- Atomic updates
- Average loop length
- Averages/Mean angle
- Averages/Mean time of day
- Averages/Median
- Averages/Mode
- Averages/Pythagorean means
- Averages/Simple moving average

### B

- Balanced ternary
- Barnsley fern
- Base64 decode data
- Benford's law
- Best shuffle
- Bin given limits
- Binary search
- Binary strings
- Biorhythms
- Bitcoin/address validation
- Bitcoin/public point to address
- Bitmap
- Bitmap/Bresenham's line algorithm
- Bitmap/Bézier curves/Cubic
- Bitmap/Bézier curves/Quadratic
- Bitmap/Flood fill
- Bitmap/Histogram
- Bitmap/Midpoint circle algorithm
- Bitmap/PPM conversion through a pipe
- Bitmap/Read a PPM file
- Bitmap/Read an image through a pipe
- Bitmap/Write a PPM file
- Bitwise IO
- Box the compass
- Brace expansion
- Brazilian numbers
- Break OO privacy
- Brownian tree
- Bulls and cows
- Bulls and cows/Player
- Burrows–Wheeler transform

### C

- CSV data manipulation
- CSV to HTML translation
- Calendar
- Calendar - for "REAL" programmers
- Calkin-Wilf sequence
- Call a foreign-language function
- Call a function in a shared library
- Canny edge detector
- Canonicalize CIDR
- Carmichael 3 strong pseudoprimes
- Casting out nines
- Catmull–Clark subdivision surface
- Chaocipher
- Chaos game
- Chat server
- Check Machin-like formulas
- Check that file exists
- Checkpoint synchronization
- Chernick's Carmichael numbers
- Cheryl's birthday
- Chinese remainder theorem
- Chinese zodiac
- Cholesky decomposition
- Chowla numbers
- Circles of given radius through two points
- Circular primes
- Cistercian numerals
- Classes
- Closest-pair problem
- Collections
- Color of a screen pixel
- Color quantization
- Color wheel
- Colour bars/Display
- Colour pinstripe/Display
- Colour pinstripe/Printer
- Combinations and permutations
- Command-line arguments
- Commatizing numbers
- Compare length of two strings
- Compare sorting algorithms' performance
- Compiler/AST interpreter
- Compiler/code generator
- Compiler/lexical analyzer
- Compiler/syntax analyzer
- Compiler/virtual machine interpreter
- Concurrent computing
- Conjugate transpose
- Consecutive primes with ascending or descending differences
- Constrained genericity
- Constrained random points on a circle
- Continued fraction/Arithmetic/Construct from rational number
- Convex hull
- Conway's Game of Life
- Copy stdin to stdout
- Count the coins
- Cramer's rule
- Create a file
- Create a file on magnetic tape
- Create an HTML table
- Create an object at a given address
- Cuban primes
- Cumulative standard deviation
- Currency
- Cut a rectangle
- Cyclotomic polynomial

### D

- DNS query
- Date format
- Date manipulation
- De Bruijn sequences
- Deal cards for FreeCell
- Death Star
- Deconvolution/1D
- Deconvolution/2D+
- Deepcopy
- Define a primitive data type
- Delegates
- Delete a file
- Deming's Funnel
- Detect division by zero
- Determinant and permanent
- Determine if a string has all unique characters
- Determine if a string is squeezable
- Determine if only one instance is running
- Determine if two triangles overlap
- Determine sentence type
- Dice game probabilities
- Dijkstra's algorithm
- Dinesman's multiple-dwelling problem
- Dining philosophers
- Discordian date
- Display a linear combination
- Display an outline as a nested table
- Distributed programming
- Diversity prediction theorem
- Documentation
- Doubly-linked list/Definition
- Doubly-linked list/Element definition
- Doubly-linked list/Element insertion
- Doubly-linked list/Traversal
- Draw a clock
- Draw a cuboid
- Draw a pixel
- Draw a rotating cube
- Draw a sphere
- Dutch national flag problem

### E

- EKG sequence convergence
- Eban numbers
- Echo server
- Eertree
- Egyptian fractions
- Element-wise operations
- Elementary cellular automaton/Infinite length
- Elementary cellular automaton/Random Number Generator
- Elliptic Curve Digital Signature Algorithm
- Elliptic curve arithmetic
- Empty directory
- Enforced immutability
- Entropy
- Entropy/Narcissist
- Enumerations
- Environment variables
- Equilibrium index
- Esthetic numbers
- Euler's constant 0.5772...
- Euler's identity
- Euler's sum of powers conjecture
- Euler method
- Events
- Evolutionary algorithm
- Executable library
- Execute SNUSP
- Execute a Markov algorithm
- Exponentiation with infix operators in (or operating on) the base
- Extensible prime generator
- Extreme floating point values

### F

- FASTA format
- FTP
- Faces from a mesh
- Factors of a Mersenne number
- Fast Fourier transform
- Faulhaber's formula
- Faulhaber's triangle
- Feigenbaum constant calculation
- Fermat numbers
- Fibonacci word
- Fibonacci word/fractal
- File extension is in extensions list
- File input/output
- File modification time
- File size
- File size distribution
- Find Chess960 starting position identifier
- Find common directory path
- Find duplicate files
- Find if a point is within a triangle
- Find largest left truncatable prime in a given base
- Find palindromic numbers in both binary and ternary bases
- Find the intersection of a line with a plane
- Find the intersection of two lines
- First-class functions
- First-class functions/Use numbers analogously
- First class environments
- First perfect square in base n with n unique digits
- First power of 2 that has leading decimal digits of 12
- Fivenum
- Fixed length records
- Flipping bits game
- Flow-control structures
- Floyd-Warshall algorithm
- Forest fire
- Fork
- Formal power series
- Formatted numeric output
- Fortunate numbers
- Four bit adder
- Four is magic
- Four is the number of letters in the ...
- Fraction reduction
- French Republican calendar
- Function frequency
- Functional coverage tree

### G

- GUI/Maximum window dimensions
- GUI component interaction
- GUI enabling/disabling of controls
- Galton box animation
- Gamma function
- Gapful numbers
- Gauss-Jordan matrix inversion
- Gaussian elimination
- General FizzBuzz
- Generate Chess960 starting position
- Generate random chess position
- Globally replace text in several files
- Go Fish
- Graph colouring
- Grayscale image
- Greatest subsequential sum
- Greyscale bars/Display
- Guess the number/With feedback
- Guess the number/With feedback (player)

### H

- HTTP
- HTTPS
- HTTPS/Authenticated
- HTTPS/Client-authenticated
- Hamming numbers
- Handle a signal
- Hash from two arrays
- Hash join
- Haversine formula
- Hello world/Graphical
- Hello world/Line printer
- Hello world/Standard error
- Hello world/Web server
- Here document
- Heronian triangles
- Hickerson series of almost integers
- Hofstadter Figure-Figure sequences
- Holidays related to Easter
- Honeycombs
- Horizontal sundial calculations
- Horner's rule for polynomial evaluation
- Host introspection
- Hostname
- Hough transform
- Huffman coding
- Humble numbers
- Hunt the Wumpus

### I

### J

### K

- K-d tree
- K-means++ clustering
- Kernighans large earthquake problem
- Keyboard input/Flush the keyboard buffer
- Keyboard input/Keypress check
- Keyboard input/Obtain a Y or N response
- Keyboard macros
- Knapsack problem/0-1
- Knapsack problem/Bounded
- Knapsack problem/Continuous
- Knapsack problem/Unbounded
- Knight's tour
- Knuth's algorithm S
- Knuth's power tree
- Kolakoski sequence
- Kosaraju
- Kronecker product
- Kronecker product based fractals

### L

- LU decomposition
- LZW compression
- Langton's ant
- Largest number divisible by its digits
- Last letter-first letter
- Latin Squares in reduced form
- Latin Squares in reduced form/Randomizing using Jacobson and Matthews’ Technique
- Law of cosines - triples
- Legendre prime counting function
- Levenshtein distance
- Levenshtein distance/Alignment
- Linear congruential generator
- List comprehensions
- List rooted trees
- Literals/Floating point
- Long primes
- Longest common subsequence
- Longest common substring
- Longest increasing subsequence
- Longest string challenge
- Loops/Increment loop index within loop body
- Loops/With multiple ranges
- Loops/Wrong ranges
- Lucas-Lehmer test
- Lucky and even lucky numbers
- Ludic numbers
- Lychrel numbers

### M

- MAC Vendor Lookup
- MD4
- MD5
- MD5/Implementation
- Machine code
- Mad Libs
- Magic squares of doubly even order
- Magic squares of odd order
- Magic squares of singly even order
- Magnanimous numbers
- Main step of GOST 28147-89
- Make directory path
- Man or boy test
- Mandelbrot set
- Map range
- Mastermind
- Matrix-exponentiation operator
- Matrix chain multiplication
- Matrix digital rain
- Matrix multiplication
- Maximum triangle path sum
- Mayan calendar
- Mayan numerals
- Maze generation
- Maze solving
- Median filter
- Memory allocation
- Memory layout of a data structure
- Menu
- Merge and aggregate datasets
- Mertens function
- Metallic ratios
- Metered concurrency
- Metronome
- Mian-Chowla sequence
- Miller–Rabin primality test
- Mind boggling card trick
- Minesweeper game
- Minimal steps down to 1
- Minimum positive multiple in base 10 using only 0 and 1
- Minkowski question-mark function
- Modified random distribution
- Monads/List monad
- Monads/Maybe monad
- Monads/Writer monad
- Monty Hall problem
- Morse code
- Motzkin numbers
- Mouse position
- Multi-dimensional array
- Multiple distinct objects
- Multiple regression
- Multiplicative order
- Multisplit
- Munching squares
- Musical scale
- Mutex
- Möbius function

### N

- N-queens problem
- N-smooth numbers
- Named parameters
- Natural sorting
- Nautical bell
- Negative base numbers
- Nested function
- Nested templated data
- Next highest int from digits
- Nim game
- Non-decimal radices/Input
- Non-decimal radices/Output
- Non-transitive dice
- Nonoblock
- Nonogram solver
- Nth root
- Null object
- Number reversal game
- Numbers with equal rises and falls
- Numeric error propagation
- Numerical and alphabetical suffixes
- Numerical integration
- Numerical integration/Gauss-Legendre Quadrature

### O

### P

- P-Adic numbers, basic
- P-Adic square roots
- P-value correction
- Padovan n-step number sequences
- Palindrome dates
- Palindromic gapful numbers
- Pancake numbers
- Paraffins
- Parallel brute force
- Parallel calculations
- Parametric polymorphism
- Parametrized SQL statement
- Parse an IP Address
- Parsing/RPN to infix conversion
- Parsing/Shunting-yard algorithm
- Partition an integer x into n primes
- Partition function P
- Pascal's triangle/Puzzle
- Pascal matrix generation
- Password generator
- Pathological floating point problems
- Pattern matching
- Peaceful chess queen armies
- Pell's equation
- Penney's game
- Pentomino tiling
- Percentage difference between images
- Percolation/Bond percolation
- Percolation/Mean cluster density
- Percolation/Mean run density
- Percolation/Site percolation
- Peripheral drift illusion
- Perlin noise
- Permutation test
- Permutations/Rank of a permutation
- Permutations by swapping
- Pierpont primes
- Pig the dice game
- Pig the dice game/Player
- Pinstripe/Display
- Pinstripe/Printer
- Pisano period
- Plasma effect
- Play recorded sounds
- Playfair cipher
- Plot coordinate pairs
- Pointers and references
- Poker hand analyser
- Polymorphic copy
- Polymorphism
- Polynomial long division
- Polynomial regression
- Polyspiral
- Pragmatic directives
- Prime conspiracy
- Primes - allocate descendants to their ancestors
- Primorial numbers
- Problem of Apollonius
- Program name
- Program termination
- 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
- Pythagoras tree
- Pythagorean quadruples
- Pythagorean triples

### R

- RCRPG
- RIPEMD-160
- RSA code
- Ramanujan's constant
- Ramanujan primes/twins
- Ramer-Douglas-Peucker line simplification
- Random Latin squares
- Random number generator (device)
- Random numbers
- Random sentence from book
- Range consolidation
- Range expansion
- Range extraction
- Ranking methods
- 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
- Record sound
- Reduced row echelon form
- Reflection/Get source
- Reflection/List methods
- Reflection/List properties
- Regular expressions
- Remove lines from a file
- Rename a file
- Rendezvous
- Resistor mesh
- Respond to an unknown method call
- Retrieve and search chat history
- Rock-paper-scissors
- Roots of a function
- Roots of a quadratic function
- Roots of unity
- Rosetta Code/Count examples
- Rosetta Code/Find bare lang tags
- Rosetta Code/Find unimplemented tasks
- Rosetta Code/Fix code tags
- Rosetta Code/Rank languages by number of users
- Rosetta Code/Rank languages by popularity
- Runge-Kutta method
- Runtime evaluation/In an environment

### S

- S-expressions
- SEDOLs
- SHA-1
- SHA-256
- SHA-256 Merkle tree
- SOAP
- SQL-based authentication
- Safe addition
- Safe primes and unsafe primes
- Sailors, coconuts and a monkey problem
- Same fringe
- Scope/Function names and labels
- Scope modifiers
- Search a list
- Search a list of records
- Secure temporary file
- Self numbers
- Send an unknown method call
- Send email
- Sequence: nth number with exactly n divisors
- Sequence: smallest number greater than previous term with exactly n divisors
- Sequence of primorial primes
- Set consolidation
- Set of real numbers
- Set puzzle
- Set right-adjacent bits
- Sexy primes
- Shoelace formula for polygonal area
- Short-circuit evaluation
- Shortest common supersequence
- Show the epoch
- Simple database
- Simple windowed application
- Simulate input/Keyboard
- Simulate input/Mouse
- Singleton
- Singly-linked list/Element definition
- Singly-linked list/Element insertion
- Singly-linked list/Traversal
- Sleep
- Smarandache prime-digital sequence
- Smith numbers
- Snake
- Sockets
- Sokoban
- Solve a Hidato puzzle
- Solve a Holy Knight's tour
- Solve a Hopido puzzle
- Solve a Numbrix puzzle
- Solve the no connection puzzle
- Sort a list of object identifiers
- Sort an array of composite structures
- Sort an outline at every level
- Sort disjoint sublist
- Sorting algorithms/Bead sort
- Sorting algorithms/Cocktail sort
- Sorting algorithms/Cocktail sort with shifting bounds
- Sorting algorithms/Comb sort
- Sorting algorithms/Patience sort
- Sorting algorithms/Permutation sort
- Sorting algorithms/Radix sort
- Sorting algorithms/Shell sort
- Sorting algorithms/Sleep sort
- Sorting algorithms/Stooge sort
- Sorting algorithms/Strand sort
- Soundex
- Sparkline in unicode
- Speech synthesis
- Spelling of ordinal numbers
- Spinning rod animation/Text
- Spiral matrix
- Square-free integers
- Square form factorization
- Stable marriage problem
- State name puzzle
- Statistics/Basic
- Statistics/Normal distribution
- Stem-and-leaf plot
- Stern-Brocot sequence
- Straddling checkerboard
- Strassen's algorithm
- Stream merge
- String comparison
- String interpolation (included)
- String length
- Strip block comments
- Strip comments from a string
- Strip control codes and extended characters from a string
- Strong and weak primes
- Subleq
- Subtractive generator
- Successive prime differences
- Sudoku
- Suffixation of decimal numbers
- Sum and product puzzle
- Sum of elements below main diagonal of matrix
- Sum to 100
- Summarize and say sequence
- Summarize primes
- Super-d numbers
- Superellipse
- Superpermutation minimisation
- Sutherland-Hodgman polygon clipping
- Sylvester's sequence
- Synchronous concurrency

### T

- Table creation/Postal addresses
- Take notes on the command line
- Tarjan
- Taxicab numbers
- Teacup rim text
- Terminal control/Coloured text
- Terminal control/Cursor movement
- Terminal control/Dimensions
- Terminal control/Display an extended character
- Terminal control/Positional read
- Terminal control/Preserve screen
- Terminal control/Unicode output
- Text processing/1
- Text processing/2
- Text processing/Max licenses in use
- Textonyms
- The ISAAC Cipher
- The Name Game
- The sieve of Sundaram
- Thiele's interpolation formula
- Tic-tac-toe
- Time a function
- Tokenize a string with escaping
- Tonelli-Shanks algorithm
- Top rank per group
- Topic variable
- Topological sort
- Topswops
- Total circles area
- Trabb Pardo–Knuth algorithm
- Tree datastructures
- Tree traversal
- Truncate a file
- Twelve statements
- Twin primes
- Two bullet roulette

### U

- UPC
- URL decoding
- URL encoding
- URL parser
- UTF-8 encode and decode
- Ukkonen’s suffix tree construction
- Ulam spiral (for primes)
- Undefined values
- Unicode strings
- Unicode variable names
- Universal Turing machine
- Unix/ls
- Unprimeable numbers
- Untouchable numbers
- Update a configuration file
- Use another language to call a function

### V

### W

- Walk a directory/Non-recursively
- Walk a directory/Recursively
- War card game
- Water collected between towers
- Web scraping
- Weird numbers
- Wilson primes of order n
- Window creation
- Window creation/X11
- Window management
- Wireworld
- Word frequency
- Word ladder
- Word search
- Word wheel
- Wordiff
- World Cup group stage
- Write entire file
- Write float arrays to a text file
- Write to Windows event log

### 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 Quackery (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

- A* search algorithm
- ADFGVX cipher
- Addition-chain exponentiation
- Addition chains
- Air mass
- Append numbers at same position in strings
- Arithmetic coding/As a generalized change of radix
- Aspect oriented programming
- Assertions in design by contract
- Audio alarm
- Audio frequency generator
- Audio overlap loop

### B

### C

- CLI-based maze-game
- Camel case and snake case
- Card shuffles
- Changeable words
- Chebyshev coefficients
- Checksumcolor
- Chemical calculator
- Chess player
- Cipolla's algorithm
- Code Golf: Code Golf
- Code segment unload
- Collect and sort square numbers in ascending order from three lists
- Combinations with repetitions/Square digit chain
- 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 n)
- Continued fraction/Arithmetic/G(matrix ng, continued fraction n1, continued fraction n2)
- Coprime triplets
- Count the coins/0-1
- Cousin primes
- Create an object/Native demonstration
- Create your own text control codes
- Cubic Special Primes
- Cullen and Woodall numbers
- Curve that touches three points
- Cycle detection
- Cyclops numbers

### D

- Data Encryption Standard
- Dating agency
- Day of the week of Christmas and New Year
- Days between dates
- Decimal floating point number to binary
- Decision tables
- 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
- Draw pixel 2

### E

### F

- Fibonacci heap
- Fibonacci matrix-exponentiation
- Find URI in text
- Find adjacent primes which differ by a square integer
- Find first and last set bit of a long integer
- Find first missing positive
- Find minimum number of coins that make a given value
- Find prime numbers of the form n*n*n+2
- Find square difference
- Find squares n where n+1 is prime
- Find words which contain the most consonants
- Find words which contains all the vowels
- Find words which contains more than 3 e vowels
- Finite state machine
- First 9 Prime Fibonacci Number
- Free polyominoes enumeration
- Frobenius numbers

### G

### I

### L

- Largest difference between adjacent primes
- Largest five adjacent number
- Largest palindrome product
- Largest prime factor
- Largest product in a grid
- Last list item
- Launch rocket with countdown and acceleration in stdout
- Length of an arc between two angles
- Line circle intersection
- Linux CPU utilization
- Logistic curve fitting in epidemiology
- Long stairs
- Longest palindromic substrings
- Longest substrings without repeating characters

### M

- Magic constant
- Make a backup file
- Markov chain text generator
- 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
- Modulinos
- Montgomery reduction
- Morpion solitaire
- Most frequent k chars distance
- Multi-base primes
- Multidimensional Newton-Raphson method
- Multiline shebang
- Multiton

### N

- N-body problem
- NYSIIS
- Names to numbers
- Native shebang
- Neighbour primes
- Next special primes
- Nice primes
- Number triplets game
- 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
- Numerical integration/Adaptive Simpson's method

### O

### P

- Pandigital prime
- Parse EBNF
- Parse command-line arguments
- Particle fountain
- Particle swarm optimization
- Penrose tiling
- Perceptron
- Permutations with some identical elements
- Permuted multiples
- Piprimes
- Polynomial derivative
- Polynomial synthetic division
- 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 debugging statement
- Print itself
- Process SMIL directives in XML data
- Proof
- Pseudorandom number generator image

### R

- Railway circuit
- Ramanujan primes
- Ramsey's theorem
- Range modifications
- Raster bars
- Readline interface
- Recursive descent parser generator
- Remote agent/Agent interface
- Remote agent/Agent logic
- Remote agent/Simulation
- Repunit primes
- Resistance calculator
- Resistance network calculator
- Reverse the gender of a string
- 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
- Run as a daemon or service
- Ruth-Aaron numbers

### S

- Safe and Sophie Germain primes
- Safe mode
- Sanitize user input
- Segmentation fault protection
- Selective file copy
- Separate the house number from the street name
- Simulated annealing
- Sine wave
- Singly-linked list/Element removal
- 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
- Snake and Ladder
- Solve a Rubik's Cube
- Solve equations with substitution method
- Solve triangle solitare puzzle
- Solving coin problems
- Sort primes from list to a list
- Sort the letters of string in alphabetical order
- Sorting algorithms/Cycle sort
- Sorting algorithms/Tree sort on a linked list
- Special Divisors
- Special factorials
- Special neighbor primes
- Special pythagorean triplet
- Spoof game
- Square root by hand
- Starting a web browser
- Steady Squares
- Strange numbers
- Strange plus numbers
- Strange unique prime triplets
- Subset sum problem
- Substring primes
- Suffix tree
- Sum data type
- 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
- Sunflower fractal

### T

- Table creation
- Tamagotchi emulator
- Terminal control/Restricted width positional input/No wrapping
- Terminal control/Restricted width positional input/With wrapping
- Tetris
- Text between
- Text completion
- Text to HTML
- Three word location
- Time-based one-time password algorithm
- Topological sort/Extracted top item
- Transportation problem
- Tropical algebra overloading
- Type detection

### U

- URL shortener
- Ulam numbers
- Ultra useful primes
- Unicode polynomial equation
- Unique characters
- Unique characters in each string
- Unit testing
- Uno (Card Game)
- Untrusted environment
- Useless instructions
- User defined pipe and redirection operators
- Using a speech engine to highlight words
- Using the Meetup.com API

### W

## Requiring Attention[edit]

### Examples[edit]

These tasks have implementations in Quackery, 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.

### No pages found.

### Other pages[edit]

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

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## Not Considered[edit]

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

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## End of List[edit]

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