# Reports:Tasks not implemented in Jq

**Awareness**

If

**Jq**is a language you like, or are interested in, please inform your fellow members of the Jq community; this page can't be emptied without your and their participation.

## Contents

## Not implemented[edit]

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

### A

- ASCII art diagram converter
- AVL tree
- Abbreviations, automatic
- Abbreviations, easy
- Abbreviations, simple
- Abelian sandpile model
- Abelian sandpile model/Identity
- Abstract type
- Abundant odd numbers
- Accumulator factory
- Active Directory/Connect
- Active Directory/Search for a user
- Active object
- Address of a variable
- Angle difference between two bearings
- Angles (geometric), normalization and conversion
- Animate a pendulum
- Animation
- Anti-primes
- Append a record to the end of a text file
- Apply a digital filter (direct form II transposed)
- Arbitrary-precision integers (included)
- Archimedean spiral
- Arena storage pool
- Arithmetic-geometric mean/Calculate Pi
- Arithmetic/Rational
- Assertions
- Atomic updates
- Attractive numbers
- Average loop length
- Averages/Simple moving average

### B

- Balanced brackets
- Balanced ternary
- Barnsley fern
- Bell numbers
- Bin given limits
- Bioinformatics/Sequence mutation
- 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
- Bitwise operations
- Box the compass
- Brace expansion
- Brazilian numbers
- Break OO privacy
- Brownian tree
- Bulls and cows
- Bulls and cows/Player
- Burrows–Wheeler transform

### C

- CRC-32
- CUSIP
- Caesar cipher
- Calendar
- Calendar - for "REAL" programmers
- Calkin-Wilf sequence
- Call a foreign-language function
- Call a function in a shared library
- Call an object method
- Canny edge detector
- Canonicalize CIDR
- Carmichael 3 strong pseudoprimes
- Catmull–Clark subdivision surface
- Chaocipher
- Chaos game
- Chat server
- Check Machin-like formulas
- Check input device is a terminal
- Check output device is a terminal
- Check that file exists
- Checkpoint synchronization
- Chernick's Carmichael numbers
- Cheryl's birthday
- Chinese zodiac
- Chowla numbers
- Church numerals
- Circular primes
- Cistercian numerals
- Classes
- Closures/Value capture
- Color of a screen pixel
- Color quantization
- Color wheel
- Colour bars/Display
- Colour pinstripe/Display
- Colour pinstripe/Printer
- Commatizing numbers
- Compare sorting algorithms' performance
- Compile-time calculation
- Compiler/AST interpreter
- Compiler/code generator
- Compiler/lexical analyzer
- Compiler/syntax analyzer
- Compiler/virtual machine interpreter
- Concurrent computing
- Constrained genericity
- Constrained random points on a circle
- Continued fraction/Arithmetic/Construct from rational number
- Convert decimal number to rational
- Convex hull
- Count in factors
- Cramer's rule
- Create a file
- Create a file on magnetic tape
- Create an object at a given address
- Cuban primes
- Currency
- Cut a rectangle
- Cyclotomic polynomial

### D

- DNS query
- Damm algorithm
- De Bruijn sequences
- Deal cards for FreeCell
- Death Star
- Deconvolution/1D
- Deconvolution/2D+
- Delegates
- Delete a file
- Deming's Funnel
- Determine if only one instance is running
- Determine if two triangles overlap
- Dice game probabilities
- Dijkstra's algorithm
- Dining philosophers
- Discordian date
- 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
- Dutch national flag problem

### E

- EKG sequence convergence
- Eban numbers
- Echo server
- Eertree
- Egyptian division
- Egyptian fractions
- Elementary cellular automaton/Infinite length
- Elementary cellular automaton/Random Number Generator
- Elliptic Curve Digital Signature Algorithm
- Elliptic curve arithmetic
- Empty directory
- Entropy/Narcissist
- Events
- Evolutionary algorithm
- Executable library
- Execute Brain****
- Execute HQ9+
- Execute SNUSP
- Execute a Markov algorithm
- Execute a system command
- Exponentiation with infix operators in (or operating on) the base
- Extend your language

### F

- FTP
- Faces from a mesh
- Factorial base numbers indexing permutations of a collection
- Factorions
- Factors of a Mersenne number
- Farey sequence
- Faulhaber's formula
- Faulhaber's triangle
- Fermat numbers
- Fibonacci word/fractal
- File modification time
- File size distribution
- Find duplicate files
- 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
- First-class functions
- First perfect square in base n with n unique digits
- First power of 2 that has leading decimal digits of 12
- Fivenum
- Flipping bits game
- Forest fire
- Fork
- Four is magic
- Four is the number of letters in the ...
- Fraction reduction
- Fractran
- French Republican calendar
- Function frequency
- Function prototype
- Functional coverage tree
- Fusc sequence

### G

- GUI/Maximum window dimensions
- GUI component interaction
- GUI enabling/disabling of controls
- Galton box animation
- Gapful numbers
- Gauss-Jordan matrix inversion
- Gaussian elimination
- General FizzBuzz
- Generate Chess960 starting position
- Generate random chess position
- Get system command output
- Go Fish
- Graph colouring
- Gray code
- Grayscale image
- Greyscale bars/Display
- Guess the number/With feedback
- Guess the number/With feedback (player)

### H

- HTTP
- HTTPS
- HTTPS/Authenticated
- HTTPS/Client-authenticated
- Handle a signal
- Hello world/Line printer
- Hello world/Web server
- Hilbert curve
- History variables
- Hofstadter-Conway $10,000 sequence
- Hofstadter Figure-Figure sequences
- Holidays related to Easter
- Honeycombs
- Horizontal sundial calculations
- Horner's rule for polynomial evaluation
- Host introspection
- Hough transform
- Huffman coding
- Humble numbers
- Hunt the Wumpus

### I

- ISBN13 check digit
- Image convolution
- Image noise
- Imaginary base numbers
- Increasing gaps between consecutive Niven numbers
- Index finite lists of positive integers
- Inheritance/Multiple
- Inheritance/Single
- Integer overflow
- Interactive programming
- Intersecting number wheels
- Isqrt (integer square root) of X

### 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/Bounded
- Knapsack problem/Unbounded
- Knight's tour
- Knuth's algorithm S
- Knuth's power tree
- Knuth shuffle
- Koch curve
- Kolakoski sequence
- Kosaraju
- Kronecker product based fractals

### L

- Lah numbers
- Largest number divisible by its digits
- Latin Squares in reduced form
- Law of cosines - triples
- Levenshtein distance/Alignment
- List rooted trees
- Long literals, with continuations
- Long primes
- Long year
- 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

### M

- MAC Vendor Lookup
- MD4
- MD5
- MD5/Implementation
- Machine code
- Mad Libs
- Magic 8-ball
- Magic squares of doubly even order
- Magic squares of singly even order
- Main step of GOST 28147-89
- Make directory path
- Man or boy test
- Mastermind
- Matrix chain multiplication
- Matrix digital rain
- Mayan numerals
- Maze generation
- Maze solving
- Median filter
- Memory allocation
- Memory layout of a data structure
- Merge and aggregate datasets
- Mertens function
- Metallic ratios
- Metaprogramming
- Metered concurrency
- Metronome
- Mian-Chowla sequence
- Miller–Rabin primality test
- Mind boggling card trick
- Minesweeper game
- Minimal steps down to 1
- Minkowski question-mark function
- Modified random distribution
- Modular arithmetic
- Modular exponentiation
- Modular inverse
- Monads/List monad
- Monads/Maybe monad
- Monads/Writer monad
- Monte Carlo methods
- Monty Hall problem
- Morse code
- Mouse position
- Multiple regression
- Multiplication tables
- Multiplicative order
- Musical scale
- Mutex

### N

- N-smooth numbers
- Narcissist
- Nautical bell
- Nested templated data
- Next highest int from digits
- Nim game
- Nimber arithmetic
- Non-decimal radices/Input
- Non-decimal radices/Output
- Non-transitive dice
- Nonoblock
- Nonogram solver
- 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
- Padovan sequence
- Palindrome dates
- Palindromic gapful numbers
- Pancake numbers
- Parallel brute force
- Parallel calculations
- Parametric polymorphism
- Parametrized SQL statement
- Parse an IP Address
- Parsing/RPN calculator algorithm
- Parsing/RPN to infix conversion
- Parsing/Shunting-yard algorithm
- Partial function application
- Partition an integer x into n primes
- Partition function P
- Pascal's triangle/Puzzle
- Password generator
- Pattern matching
- Peaceful chess queen armies
- Peano curve
- Pell's equation
- Penney's game
- Pentagram
- Percentage difference between images
- Percolation/Bond percolation
- Percolation/Mean cluster density
- Percolation/Mean run density
- Percolation/Site percolation
- Perfect shuffle
- Perfect totient numbers
- Perlin noise
- Permutations/Rank of a permutation
- Pick random element
- Pierpont primes
- Pig the dice game
- Pig the dice game/Player
- Pinstripe/Display
- Pinstripe/Printer
- Plasma effect
- Play recorded sounds
- Playfair cipher
- Playing cards
- Pointers and references
- Poker hand analyser
- Polymorphic copy
- Polynomial long division
- Polynomial regression
- Polyspiral
- Pragmatic directives
- Primality by Wilson's theorem
- Prime conspiracy
- Primes - allocate descendants to their ancestors
- Primorial numbers
- Probabilistic choice
- Program name
- Pseudo-random numbers/Combined recursive generator MRG32k3a
- Pseudo-random numbers/PCG32
- Pseudo-random numbers/Xorshift star
- Pythagoras tree

### R

- RCRPG
- RIPEMD-160
- RPG attributes generator
- RSA code
- Ramanujan's constant
- Ramer-Douglas-Peucker line simplification
- Random Latin squares
- Random number generator (included)
- Random sentence from book
- Range consolidation
- Rare numbers
- Rate counter
- Ray-casting algorithm
- Recaman's sequence
- Record sound
- Reduced row echelon form
- Reflection/Get source
- Reflection/List methods
- Reflection/List properties
- Rename a file
- Rendezvous
- Resistor mesh
- Respond to an unknown method call
- Retrieve and search chat history
- Rock-paper-scissors
- Roman numerals/Encode
- Rosetta Code/Find bare lang tags
- Rosetta Code/Find unimplemented tasks
- Rosetta Code/Fix code tags
- Rosetta Code/Rank languages by number of users
- Runtime evaluation
- Runtime evaluation/In an environment

### S

- S-expressions
- SHA-1
- SHA-256
- SHA-256 Merkle tree
- SOAP
- SQL-based authentication
- Safe addition
- Safe primes and unsafe primes
- Scope modifiers
- Secure temporary file
- Self numbers
- Semiprime
- 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: smallest number with exactly n divisors
- Sequence of primorial primes
- Set of real numbers
- Set puzzle
- Seven-sided dice from five-sided dice
- Sexy primes
- Shoelace formula for polygonal area
- Shortest common supersequence
- Show ASCII table
- Sierpinski pentagon
- Sierpinski triangle
- Sierpinski triangle/Graphical
- Simple database
- Simple windowed application
- Simulate input/Keyboard
- Simulate input/Mouse
- Singleton
- Singly-linked list/Element definition
- Singly-linked list/Element insertion
- Sleep
- Smarandache prime-digital sequence
- Smith numbers
- Sockets
- Sokoban
- Solve a Hidato puzzle
- Solve a Holy Knight's tour
- Solve a Hopido puzzle
- Solve a Numbrix puzzle
- Sort an outline at every level
- Sort numbers lexicographically
- Sorting algorithms/Bogosort
- Sorting algorithms/Cocktail sort with shifting bounds
- Sorting algorithms/Heapsort
- Sorting algorithms/Patience sort
- Soundex
- Speech synthesis
- Spelling of ordinal numbers
- Spinning rod animation/Text
- Square Form Factorization
- Square but not cube
- Stable marriage problem
- Stack
- Stack traces
- Start from a main routine
- Statistics/Basic
- Statistics/Normal distribution
- Stirling numbers of the first kind
- Stirling numbers of the second kind
- Straddling checkerboard
- Stream merge
- Strong and weak primes
- Substitution cipher
- Subtractive generator
- Successive prime differences
- Sudoku
- Suffixation of decimal numbers
- Sum and product puzzle
- Sunflower fractal
- Super-d numbers
- Superellipse
- Superpermutation minimisation
- Sutherland-Hodgman polygon clipping
- Synchronous concurrency

### T

- Table creation/Postal addresses
- Take notes on the command line
- Tarjan
- Tau function
- Tau number
- Teacup rim text
- 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
- The ISAAC Cipher
- The Name Game
- Thiele's interpolation formula
- Thue-Morse
- Tic-tac-toe
- Time a function
- Tonelli-Shanks algorithm
- Total circles area
- Totient function
- Tree datastructures
- Tree from nesting levels
- Truncatable primes
- Truncate a file
- Truth table

### U

### V

- Validate International Securities Identification Number
- Vampire number
- Variable-length quantity
- Variable size/Get
- Variable size/Set
- Verify distribution uniformity/Chi-squared test
- Verify distribution uniformity/Naive
- Video display modes
- Vigenère cipher
- Vigenère cipher/Cryptanalysis
- Visualize a tree
- Vogel's approximation method
- Voronoi diagram

### W

### 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 Jq (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
- ABC words
- Addition-chain exponentiation
- Addition chains
- Additive primes
- Air mass
- Almkvist-Giullera formula for pi
- Alternade words
- 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
- Card shuffles
- Change e letters to i in words
- Changeable words
- Chebyshev coefficients
- Checksumcolor
- Chemical calculator
- Chess player
- Cipolla's algorithm
- Code segment unload
- Combinations with repetitions/Square digit chain
- Common list elements
- Common sorted list
- Compiler/Verifying syntax
- Consecutive Primes With Ascending Or Descending Differences
- Continued fraction/Arithmetic/G(matrix ng, continued fraction n)
- Continued fraction/Arithmetic/G(matrix ng, continued fraction n1, continued fraction n2)
- Coprime triplets
- Coprimes
- Count the coins/0-1
- Cousin primes
- Cubic Special Primes
- Curve that touches three points
- Cycle detection

### D

### F

- Fibonacci heap
- Fibonacci matrix-exponentiation
- Find first and last set bit of a long integer
- Find first missing positive
- Find if a point is within a triangle
- Find prime n for that reversed n is also prime
- Find prime numbers of the form n*n*n+2
- Find words which contains all the vowels
- Find words which contains more than 3 e vowels
- Find words which contains most consonants
- Find words which first and last three letters are equals
- Find words with alternating vowels and consonants
- Finite state machine
- Free polyominoes enumeration
- Frobenius numbers

### G

### I

### L

- Latin Squares in reduced form/Randomizing using Jacobson and Matthews’ Technique
- 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
- Longest common suffix
- Longest palindromic substrings

### M

- Magnanimous numbers
- Make a backup file
- Markov chain text generator
- Mayan calendar
- Mersenne primes
- Minimum positive multiple in base 10 using only 0 and 1
- Modulinos
- Montgomery reduction
- Morpion solitaire
- Most frequent k chars distance
- Multidimensional Newton-Raphson method
- Multiline shebang
- Möbius function

### N

- N-body problem
- NYSIIS
- Names to numbers
- Neighbour primes
- Next special primes
- Nice primes
- Numbers divisible by their individual digits, but not by the product of their digits.
- Numbers which binary and ternary digit sum are prime
- Numbers with equal rises and falls
- Numbers with prime digits whose sum is 13
- Numeric separator syntax
- Numerical integration/Adaptive Simpson's method

### P

- Palindromic primes
- Parse EBNF
- Parse command-line arguments
- Particle swarm optimization
- Penrose tiling
- Pentomino tiling
- Perceptron
- Permutations with some identical elements
- Piprimes
- Pisano period
- Polynomial synthetic division
- Powerful numbers
- Practical numbers
- Price list behind API
- Prime triplets
- Prime words
- Primes which sum of digits is 25
- Primes with digits in nondecreasing order
- Print debugging statement
- Print itself
- Process SMIL directives in XML data
- Product of divisors
- Proof
- Pseudo-random numbers/Splitmix64
- Pseudorandom number generator image

### R

- Railway circuit
- Ramsey's theorem
- Range modifications
- Raster bars
- Readline interface
- Recursive descent parser generator
- Remote agent/Agent interface
- Remote agent/Agent logic
- Remote agent/Simulation
- Remove vowels from a string
- Resistance calculator
- Resistance network calculator
- Reverse the gender of a string
- Robots
- Rosetta Code/List authors of task descriptions
- Rosetta Code/Run examples
- Rosetta Code/Tasks without examples
- Run as a daemon or service

### S

- Safe mode
- Sattolo cycle
- Selective file copy
- Self-hosting compiler
- Separate the house number from the street name
- Shift list elements to left by 3
- Show the (decimal) value of a number of 1s appended with a 3, then squared
- Sierpinski arrowhead curve
- Sierpinski curve
- Sierpinski square curve
- Simulated annealing
- Sine wave
- Singly-linked list/Element removal
- Sleeping Beauty problem
- Smallest enclosing circle problem
- Smallest numbers
- Smallest power of 6 whose decimal expansion contains n
- Smallest square that begins with n
- Snake
- Snake and Ladder
- Solve a Rubik's Cube
- Solve triangle solitare puzzle
- Solving coin problems
- Sorting algorithms/Cycle sort
- Sorting algorithms/Tree sort on a linked list
- Special Divisors
- Special factorials
- Spoof game
- Square root by hand
- Starting a web browser
- Strange numbers
- Strange plus numbers
- Strange unique prime triplets
- Strassen's algorithm
- Subset sum problem
- Substring primes
- Suffix tree
- Sum data type
- Sum of divisors
- Sum of the digits of n is substring of n
- Summarize primes

### T

- Table creation
- Tamagotchi emulator
- Terminal control/Restricted width positional input/No wrapping
- Terminal control/Restricted width positional input/With wrapping
- Tetris
- Text completion
- Text to HTML
- Three word location
- Time-based one-time password algorithm
- Topological sort/Extracted top item
- Transportation problem
- Twin primes
- Two bullet roulette
- Two identical strings
- Two sum
- Type detection

### U

### W

## Requiring Attention[edit]

### Examples[edit]

These tasks have implementations in Jq, 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 Jq 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 Jq 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.