# Reports:Tasks not implemented in PicoLisp

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## Contents

## Not implemented[edit]

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

### 2

### A

- ASCII art diagram converter
- AVL tree
- Abbreviations, automatic
- Abbreviations, easy
- Abbreviations, simple
- Abelian sandpile model
- Abelian sandpile model/Identity
- Achilles numbers
- Aliquot sequence classifications
- Angle difference between two bearings
- Angles (geometric), normalization and conversion
- Apply a digital filter (direct form II transposed)
- Approximate equality
- Archimedean spiral
- Arithmetic numbers
- Associative array/Merging
- Attractive numbers

### B

### C

- Calkin-Wilf sequence
- Canny edge detector
- Cantor set
- Catmull–Clark subdivision surface
- Chaocipher
- Chaos game
- Check Machin-like formulas
- Check input device is a terminal
- Check output device is a terminal
- Chernick's Carmichael numbers
- Cheryl's birthday
- Chinese zodiac
- Church numerals
- Circles of given radius through two points
- Cistercian numerals
- Color quantization
- Color wheel
- Colorful numbers
- Combinations and permutations
- 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
- Composite numbers k with no single digit factors whose factors are all substrings of k
- Conjugate transpose
- Consecutive primes with ascending or descending differences
- Continued fraction/Arithmetic/Construct from rational number
- Convert decimal number to rational
- Convex hull
- Cramer's rule
- Cuban primes
- Cullen and Woodall numbers
- Curzon numbers
- Cut a rectangle
- Cyclops numbers
- Cyclotomic polynomial

### D

- De Bruijn sequences
- Death Star
- Deceptive numbers
- Deconvolution/2D+
- Deming's funnel
- Descending primes
- Determinant and permanent
- Determine if a string is collapsible
- Determine if a string is squeezable
- Determine if two triangles overlap
- Determine sentence type
- Dice game probabilities
- Disarium numbers
- Display a linear combination
- Display an outline as a nested table
- Diversity prediction theorem
- Dominoes
- Draw a pixel
- Draw a rotating cube
- Duffinian numbers

### E

- EKG sequence convergence
- Earliest difference between prime gaps
- Eertree
- Egyptian fractions
- Elementary cellular automaton/Infinite length
- Elementary cellular automaton/Random number generator
- Elliptic Curve Digital Signature Algorithm
- Equal prime and composite sums
- Erdös-Selfridge categorization of primes
- Euler's constant 0.5772...
- Euler's identity
- Execute Computer/Zero
- Exponentiation with infix operators in (or operating on) the base

### F

- Faces from a mesh
- Factorial base numbers indexing permutations of a collection
- Factorions
- Fairshare between two and more
- Farey sequence
- Faulhaber's formula
- Faulhaber's triangle
- Feigenbaum constant calculation
- Fibonacci word
- Fibonacci word/fractal
- File extension is in extensions list
- File size distribution
- Find Chess960 starting position identifier
- Find if a point is within a triangle
- Find largest left truncatable prime in a given base
- Find the intersection of a line with a plane
- Find the intersection of two lines
- First perfect square in base n with n unique digits
- First power of 2 that has leading decimal digits of 12
- Fixed length records
- Flipping bits game
- Floyd-Warshall algorithm
- Fortunate numbers
- Four is magic
- Four is the number of letters in the ...
- Fraction reduction
- Fractran
- French Republican calendar
- Functional coverage tree
- Fusc sequence

### G

### H

### I

- Idiomatically determine all the characters that can be used for symbols
- Idiomatically determine all the lowercase and uppercase letters
- Imaginary base numbers
- Increasing gaps between consecutive Niven numbers
- Index finite lists of positive integers
- Intersecting number wheels
- Isqrt (integer square root) of X

### J

### K

### L

- LU decomposition
- 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
- Levenshtein distance/Alignment
- List rooted trees
- Long literals, with continuations
- Long primes
- Long year
- Loops/Increment loop index within loop body
- Loops/With multiple ranges
- Loops/Wrong ranges

### M

- MAC vendor lookup
- Magic 8-ball
- Magic constant
- Magic squares of doubly even order
- Magic squares of singly even order
- Mastermind
- Matrix chain multiplication
- Matrix digital rain
- 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 multiple of m where digital sum equals m
- Minimum positive multiple in base 10 using only 0 and 1
- Minkowski question-mark function
- Modified random distribution
- Modular arithmetic
- Monads/List monad
- Monads/Maybe monad
- Monads/Writer monad
- Motzkin numbers
- Multi-base primes
- Multiplicative order
- Munching squares
- Musical scale
- Möbius function

### N

- N-smooth numbers
- Nautical bell
- Negative base numbers
- Nested templated data
- Next highest int from digits
- Nim game
- Non-transitive dice
- Nonoblock
- Nonogram solver
- Numbers which are not the sum of distinct squares
- Numbers with equal rises and falls
- Numerical and alphabetical suffixes
- Numerical integration/Gauss-Legendre Quadrature

### 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
- Particle fountain
- Partition an integer x into n primes
- Peaceful chess queen armies
- Peano curve
- Pell's equation
- Pell numbers
- Pentagram
- Pentomino tiling
- Percolation/Bond percolation
- Percolation/Mean cluster density
- Percolation/Mean run density
- Percolation/Site percolation
- Periodic table
- Peripheral drift illusion
- Perlin noise
- Permutations/Rank of a permutation
- Pierpont primes
- Pig the dice game
- Pig the dice game/Player
- Pisano period
- Plasma effect
- Playfair cipher
- Polynomial regression
- Polyspiral
- Primality by Wilson's theorem
- Prime triangle
- Primes - allocate descendants to their ancestors
- Problem of Apollonius
- Pseudo-random numbers/Combined recursive generator MRG32k3a
- Pseudo-random numbers/Middle-square method
- Pseudo-random numbers/PCG32
- Pseudo-random numbers/Xorshift star
- Pythagoras tree

### R

- RCRPG
- RPG attributes generator
- Ramanujan's constant
- Ramanujan primes/twins
- Ramer-Douglas-Peucker line simplification
- Random Latin squares
- Random sentence from book
- Range consolidation
- Ranking methods
- Rare numbers
- Recaman's sequence
- Reflection/Get source
- Repunit primes
- Resistor mesh
- Retrieve and search chat history
- Rhonda numbers
- Rosetta Code/Find bare lang tags
- Rosetta Code/Rank languages by number of users
- Runge-Kutta method
- Ruth-Aaron numbers

### S

- SHA-256 Merkle tree
- SOAP
- SQL-based authentication
- Safe primes and unsafe primes
- Sailors, coconuts and a monkey problem
- Scope/Function names and labels
- Search in paragraph's text
- Selectively replace multiple instances of a character within a string
- 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 of real numbers
- Set puzzle
- Set right-adjacent bits
- Sexy primes
- Shoelace formula for polygonal area
- Shortest common supersequence
- Show ASCII table
- Sierpinski arrowhead curve
- Sierpinski pentagon
- Sierpinski square curve
- Simple turtle graphics
- Sleeping Beauty problem
- Smallest number k such that k+2^m is composite for all m less than k
- Smarandache prime-digital sequence
- Snake
- Solve a Holy Knight's tour
- Solve a Hopido puzzle
- Solve a Numbrix puzzle
- Solve the no connection puzzle
- Sort an outline at every level
- Sorting Algorithms/Circle Sort
- Sorting algorithms/Cocktail sort with shifting bounds
- Spelling of ordinal numbers
- Square-free integers
- Square but not cube
- Square form factorization
- Statistics/Normal distribution
- Stirling numbers of the first kind
- Stirling numbers of the second kind
- Strassen's algorithm
- Strong and weak primes
- Successive prime differences
- Sudan function
- Suffixation of decimal numbers
- Sum and product puzzle
- Sum of elements below main diagonal of matrix
- Sum to 100
- Summarize primes
- Super-d numbers
- Superellipse
- Superpermutation minimisation
- Sutherland-Hodgman polygon clipping
- Sylvester's sequence

### T

### 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 PicoLisp (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
- ADFGVX cipher
- Addition-chain exponentiation
- Addition chains
- Air mass
- Alternade words
- Anadromes
- Anagram generator
- Append numbers at same position in strings
- Arithmetic coding/As a generalized change of radix
- Arithmetic derivative
- Aspect oriented programming
- Assertions in design by contract
- Audio alarm
- Audio frequency generator
- Audio overlap loop
- Autogram checker

### B

- B-spline
- Babylonian spiral
- Bacon cipher
- Banker's algorithm
- Base 16 numbers needing a to f
- Bifid cipher
- Bilinear interpolation
- Binary coded decimal
- Bioinformatics/Global alignment
- Bioinformatics/Subsequence
- Birthday problem
- Black box
- Blackjack strategy
- Boids
- Boyer-Moore string search
- Brace expansion using ranges

### C

- CLI-based maze-game
- Camel case and snake case
- Change e letters to i in words
- Changeable words
- Chebyshev coefficients
- Chemical calculator
- 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/Preprocessor
- 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 executable for a program in an interpreted language
- Create your own text control codes
- Cross compilation
- Cubic special primes
- Curve that touches three points
- Cycle detection
- Cycles of a permutation

### D

- Dating agency
- Day of the week of Christmas and New Year
- Decimal floating point number to binary
- 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
- 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 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
- 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
- Length of an arc between two angles
- Line circle intersection
- Logistic curve fitting in epidemiology
- Long stairs
- Longest common prefix
- Longest common suffix
- Longest palindromic substrings
- Longest substrings without repeating characters

### M

- Marching squares
- Markov chain text generator
- 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
- Morpion solitaire
- Mosaic matrix
- Most frequent k chars distance
- Multidimensional Newton-Raphson method
- Multiton

### N

- N-body problem
- N-queens minimum and knights and bishops
- NYSIIS
- Names to numbers
- Native shebang
- Neighbour primes
- Next special primes
- Nice 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 prime digits whose sum is 13
- 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
- Pan base non-primes
- Pandigital prime
- 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 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
- Print itself
- 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
- Red black tree sort
- Remove vowels from a string
- 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

### S

- Safe and Sophie Germain primes
- Safe mode
- Sanitize user input
- Segmentation fault protection
- Self-hosting compiler
- Separate the house number from the street name
- Show the (decimal) value of a number of 1s appended with a 3, then squared
- Sierpinski curve
- Simulated annealing
- Sine wave
- 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 hanging lantern problem
- 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
- Substring primes
- Suffix tree
- 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
- 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
- Three word location
- Topological sort/Extracted top item
- Transliterate English text using the Greek alphabet
- Transportation problem
- Triplet of three numbers
- Tropical algebra overloading
- Two identical strings

### U

### W

## Requiring Attention[edit]

### Examples[edit]

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

### C

### F

### M

### O

## End of List[edit]

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