# 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
- Additive primes
- Aliquot sequence classifications
- Almkvist-Giullera formula for pi
- Angle difference between two bearings
- Angles (geometric), normalization and conversion
- Apply a digital filter (direct form II transposed)
- Approximate equality
- Archimedean spiral
- Associative array/Merging
- Attractive numbers

### B

### C

- Calkin-Wilf sequence
- Canny edge detector
- Canonicalize CIDR
- 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
- Circular primes
- Cistercian numerals
- Color quantization
- Color wheel
- 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
- 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
- Cut a rectangle
- Cyclotomic polynomial

### D

- De Bruijn sequences
- Death Star
- Deconvolution/2D+
- Deming's Funnel
- 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
- Display a linear combination
- Display an outline as a nested table
- Diversity prediction theorem
- Draw a pixel
- Draw a rotating cube

### E

- EKG sequence convergence
- Eertree
- Egyptian fractions
- Elementary cellular automaton/Infinite length
- Elementary cellular automaton/Random Number Generator
- Elliptic Curve Digital Signature Algorithm
- Euler's constant 0.5772...
- Euler's identity
- 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

### 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

### 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
- Legendre prime counting function
- 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

- Magic 8-ball
- 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 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
- Multiplicative order
- Munching squares
- Musical scale
- 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
- Paraffins
- Parallel brute force
- Partition an integer x into n primes
- Partition function P
- Peaceful chess queen armies
- Peano curve
- Pell's equation
- Pentagram
- Percolation/Bond percolation
- Percolation/Mean cluster density
- Percolation/Mean run density
- Percolation/Site percolation
- 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
- Primes - allocate descendants to their ancestors
- Problem of Apollonius
- Pseudo-random numbers/Combined recursive generator MRG32k3a
- 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
- Resistor mesh
- Retrieve and search chat history
- Rosetta Code/Find bare lang tags
- Rosetta Code/Rank languages by number of users
- Runge-Kutta method

### 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
- 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
- Sexy primes
- Shoelace formula for polygonal area
- Shortest common supersequence
- Show ASCII table
- Sierpinski arrowhead curve
- Sierpinski pentagon
- Sierpinski square curve
- Sleeping Beauty problem
- 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
- 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
- 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
- Change e letters to i in words
- Changeable words
- Chebyshev coefficients
- Chemical calculator
- Code segment unload
- 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 your own text control codes
- Cubic Special Primes
- Curve that touches three points
- Cycle detection
- Cyclops numbers

### D

### 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 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
- 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

- Magic constant
- Markov chain text generator
- Maximum difference between adjacent elements of list
- Mine a bitcoin
- Minimum number of cells after, before, above and below NxN squares
- Minimum numbers of three lists
- Minimum primes
- Morpion solitaire
- Most frequent k chars distance
- Multi-base primes
- Multidimensional Newton-Raphson method
- Multiton

### N

- N-body problem
- NYSIIS
- Names to numbers
- Native shebang
- 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
- Numeric separator syntax
- Numerical integration/Adaptive Simpson's method

### O

### P

- Palindromic primes
- Palindromic primes in base 16
- Pandigital prime
- Particle fountain
- Particle swarm optimization
- Penrose tiling
- Pentomino 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
- Product of divisors
- Proof

### R

- Railway circuit
- Ramanujan primes
- Ramsey's theorem
- Range modifications
- Raster bars
- Readline interface
- Recursive descent parser generator
- 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 mode
- Segmentation fault protection
- 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
- Simple turtle graphics
- 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 triangle solitare puzzle
- Solving coin problems
- 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
- 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 the digits of n is substring of n
- 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
- 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.