# Reports:Tasks not implemented in Lua

**Awareness**

If

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

## Contents

## Not implemented[edit]

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

### A

### B

### C

- Calkin-Wilf sequence
- Canny edge detector
- Canonicalize CIDR
- Catmull–Clark subdivision surface
- Chat server
- Check Machin-like formulas
- Check input device is a terminal
- Checkpoint synchronization
- Chernick's Carmichael numbers
- Cholesky decomposition
- Closest-pair problem
- Color of a screen pixel
- Color quantization
- Colorful numbers
- Colour bars/Display
- Colour pinstripe/Display
- Colour pinstripe/Printer
- Combinations and permutations
- Commatizing numbers
- Compare length of two strings
- Compare sorting algorithms' performance
- Compiler/AST interpreter
- Compiler/code generator
- Compiler/syntax analyzer
- Compiler/virtual machine interpreter
- Composite numbers k with no single digit factors whose factors are all substrings of k
- Conjugate transpose
- Continued fraction/Arithmetic/Construct from rational number
- Create an object at a given address
- Cullen and Woodall numbers
- Currency
- Curzon numbers
- Cyclops numbers
- Cyclotomic polynomial

### D

- Death Star
- Deceptive numbers
- Deconvolution/2D+
- Define a primitive data type
- Deming's Funnel
- Descending primes
- Determine if only one instance is running
- Determine sentence type
- Digital root/Multiplicative digital root
- Dining philosophers
- Disarium numbers
- Discordian date
- Display an outline as a nested table
- Distributed programming
- Duffinian numbers

### E

- EKG sequence convergence
- Earliest difference between prime gaps
- 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
- Equal prime and composite sums
- Erdös-Selfridge categorization of primes
- Euler's constant 0.5772...
- Events

### F

- FTP
- Faces from a mesh
- Factorial base numbers indexing permutations of a collection
- Factorions
- Factors of a Mersenne number
- Fermat numbers
- File size distribution
- Find Chess960 starting position identifier
- Find common directory path
- Find duplicate files
- Find largest left truncatable prime in a given base
- Find palindromic numbers in both binary and ternary bases
- First perfect square in base n with n unique digits
- First power of 2 that has leading decimal digits of 12
- Fortunate numbers
- Four is the number of letters in the ...
- Fractran
- French Republican calendar
- Function frequency

### G

### H

### I

- Idiomatically determine all the characters that can be used for symbols
- Image convolution
- Image noise
- Imaginary base numbers
- Increasing gaps between consecutive Niven numbers
- Index finite lists of positive integers
- Inheritance/Single
- Integer overflow
- Intersecting number wheels
- Inverted index
- Inverted syntax

### J

### K

### L

- LU decomposition
- Lah numbers
- Largest proper divisor of n
- Latin Squares in reduced form
- Latin Squares in reduced form/Randomizing using Jacobson and Matthews’ Technique
- Legendre prime counting function
- Levenshtein distance/Alignment
- Long multiplication
- Long primes
- Long year
- Longest common substring
- Loops/With multiple ranges
- Loops/Wrong ranges
- Lucas-Lehmer test
- Lucky and even lucky numbers
- Lychrel numbers

### M

- Machine code
- Mad Libs
- Magic constant
- Magnanimous numbers
- Main step of GOST 28147-89
- Matrix digital rain
- Mayan calendar
- Mayan numerals
- Maze solving
- Median filter
- Memory allocation
- Memory layout of a data structure
- Merge and aggregate datasets
- Mertens function
- Metallic ratios
- Metered concurrency
- Metronome
- Mian-Chowla sequence
- Mind boggling card trick
- Minesweeper game
- Minimal steps down to 1
- Minimum multiple of m where digital sum equals m
- Minkowski question-mark function
- Modified random distribution
- Modular exponentiation
- Modular inverse
- Monads/List monad
- Monads/Writer monad
- Motzkin numbers
- Mouse position
- Multi-base primes
- Multiple regression
- Multiplicative order
- Mutex

### N

- N-smooth numbers
- Narcissist
- Natural sorting
- Nautical bell
- Negative base numbers
- Nested templated data
- Next highest int from digits
- Non-continuous subsequences
- Non-transitive dice
- Nonogram solver
- Numbers which are not the sum of distinct squares
- Numbers with equal rises and falls
- Numeric error propagation
- Numerical and alphabetical suffixes

### 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
- Paraffins
- Parallel brute force
- Parallel calculations
- Parameterized SQL statement
- Parametric polymorphism
- Parse an IP Address
- Particle fountain
- Partition an integer x into n primes
- Partition function P
- Pascal's triangle/Puzzle
- Pathological floating point problems
- Pattern matching
- Peaceful chess queen armies
- Pell's equation
- Pell numbers
- Pentagram
- Pentomino tiling
- Percolation/Bond percolation
- Percolation/Mean cluster density
- Percolation/Mean run density
- Percolation/Site percolation
- Perfect totient numbers
- Peripheral drift illusion
- Perlin noise
- Permutation test
- Permutations/Rank of a permutation
- Pig the dice game/Player
- Pinstripe/Printer
- Pisano period
- Play recorded sounds
- Playfair cipher
- Polymorphic copy
- Polynomial long division
- Pragmatic directives
- Prime triangle
- Primes - allocate descendants to their ancestors
- Primorial numbers
- Problem of Apollonius
- Pseudo-random numbers/Combined recursive generator MRG32k3a
- Pseudo-random numbers/Middle-square method
- Pseudo-random numbers/Splitmix64
- Pythagoras tree
- Pythagorean triples

### R

- RCRPG
- RPG attributes generator
- RSA code
- Ramanujan's constant
- Ramanujan primes/twins
- Ramer-Douglas-Peucker line simplification
- Random Latin squares
- Random number generator (device)
- Random sentence from book
- Range consolidation
- Ranking methods
- Rare numbers
- Rate counter
- Record sound
- Rendezvous
- Rep-string
- Repunit primes
- Resistor mesh
- Retrieve and search chat history
- Rhonda numbers
- Rosetta Code/Count examples
- Rosetta Code/Find bare lang tags
- Rosetta Code/Rank languages by number of users
- Rosetta Code/Rank languages by popularity
- Runge-Kutta method
- Ruth-Aaron numbers

### S

- SEDOLs
- SHA-256 Merkle tree
- SOAP
- SQL-based authentication
- Safe addition
- Search in paragraph's text
- 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
- Sequence of primorial primes
- Set puzzle
- Set right-adjacent bits
- Shortest common supersequence
- Sierpinski arrowhead curve
- Sierpinski square curve
- Simple database
- Simple turtle graphics
- Simulate input/Keyboard
- Simulate input/Mouse
- Singleton
- Singly-linked list/Element definition
- Singly-linked list/Element insertion
- Singly-linked list/Traversal
- Sleeping Beauty problem
- Smallest number k such that k+2^m is composite for all m less than k
- Snake
- Sokoban
- Solve a Hidato puzzle
- Solve a Hopido puzzle
- Solve a Numbrix puzzle
- Solve the no connection puzzle
- Sort an outline at every level
- Sorting algorithms/Cocktail sort with shifting bounds
- Sorting algorithms/Heapsort
- Sorting algorithms/Patience sort
- Sorting algorithms/Radix sort
- Sorting algorithms/Strand sort
- Sparkline in unicode
- Speech synthesis
- Spelling of ordinal numbers
- Square form factorization
- Start from a main routine
- State name puzzle
- Stirling numbers of the first kind
- Stirling numbers of the second kind
- Strassen's algorithm
- Stream merge
- Suffixation of decimal numbers
- Sum of elements below main diagonal of matrix
- Summarize primes
- Superpermutation minimisation
- Sylvester's sequence

### T

- Tarjan
- Teacup rim text
- Terminal control/Cursor movement
- Terminal control/Cursor positioning
- Terminal control/Dimensions
- Terminal control/Hiding the cursor
- Terminal control/Inverse video
- Terminal control/Positional read
- Terminal control/Preserve screen
- Terminal control/Unicode output
- Ternary logic
- The sieve of Sundaram
- Thiele's interpolation formula
- Tonelli-Shanks algorithm
- Topic variable
- Topological sort
- Total circles area
- Tree datastructures
- Tree from nesting levels
- Truth table
- Twelve statements
- Twin primes
- Two bullet roulette

### U

### V

### 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 Lua (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
- Change e letters to i in words
- Changeable words
- Checksumcolor
- 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
- Common list elements
- Common sorted list
- Compiler/Simple file inclusion pre processor
- Compiler/Verifying syntax
- 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
- Coprimes
- Count how many vowels and consonants occur in a string
- Count the coins/0-1
- Cousin primes
- Create an object/Native demonstration
- Create your own text control codes
- Cubic special primes
- Curve that touches three points
- Cycles of a permutation

### D

- Data Encryption Standard
- Dating agency
- Day of the week of Christmas and New Year
- Decimal floating point number to binary
- 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 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 contain the most consonants
- Find words which contains all the vowels
- Find words which contains more than 3 e vowels
- Find words whose first and last three letters are equal
- Find words with alternating vowels and consonants
- Finite state machine
- First 9 prime Fibonacci number
- Four sides of square
- 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
- Linux CPU utilization
- Logistic curve fitting in epidemiology
- Long stairs
- Longest common suffix
- Longest palindromic substrings
- Longest substrings without repeating characters

### M

- Make a backup file
- Matrix with two diagonals
- Maximum difference between adjacent elements of list
- Minimum number of cells after, before, above and below NxN squares
- Minimum numbers of three lists
- Minimum primes
- Montgomery reduction
- Morpion solitaire
- Mosaic matrix
- Most frequent k chars distance
- Multidimensional Newton-Raphson method
- Multiline shebang
- Multiton

### N

- N-body problem
- N-queens minimum and knights and bishops
- NYSIIS
- Names to numbers
- Native shebang
- Neighbour primes
- Next special primes
- Nimber arithmetic
- 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 binary and ternary digit sum are prime
- Numbers whose count of divisors is prime
- Numbers with same digit set in base 10 and base 16
- Numeric separator syntax
- Numerical integration/Adaptive Simpson's method

### O

### P

- Palindromic primes
- Palindromic primes in base 16
- Pandigital prime
- Parse EBNF
- Parse command-line arguments
- Particle swarm optimization
- Penrose tiling
- Permutations with repetitions
- 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 for which the sum of primes less than 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
- Process SMIL directives in XML data
- Product of divisors
- Proof

### 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
- 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

### S

- Safe and Sophie Germain primes
- Safe mode
- Sanitize user input
- Segmentation fault protection
- 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 curve
- Simulated annealing
- Sine wave
- Singly-linked list/Element removal
- Smallest enclosing circle problem
- Smallest multiple
- 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
- Solve triangle solitare puzzle
- Solving coin problems
- Sort primes from list to a list
- Sort the letters of string in alphabetical order
- Sorting algorithms/Tree sort on a linked list
- Special divisors
- 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 divisors
- 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
- Sunflower fractal

### T

- 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
- Time-based one-time password algorithm
- Topological sort/Extracted top item
- Transportation problem
- Triplet of three numbers
- Tropical algebra overloading
- Two identical strings

### U

### W

## Requiring Attention[edit]

### Examples[edit]

These tasks have implementations in Lua, 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 Lua 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 Lua was inappropriate for these tasks, or implementations of them would be unenlightening. Feel free to try your hand at them anyway.

## End of List[edit]

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