# Reports:Tasks not implemented in Smalltalk

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## Contents

## Not implemented[edit]

These are currently not implemented in Smalltalk. Please implement some if you can. If any tasks are not possible or too complex in Smalltalk, they should not be on this list. To mark a task as such, add **{{omit from|Smalltalk}}**, 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
- Abundant, deficient and perfect number classifications
- Active Directory/Connect
- Active Directory/Search for a user
- Additive primes
- Aliquot sequence classifications
- Almkvist-Giullera formula for pi
- Almost prime
- Amicable pairs
- Anagrams/Deranged anagrams
- 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)
- Archimedean spiral
- Arena storage pool
- Arithmetic-geometric mean/Calculate Pi
- Arithmetic evaluation
- Attractive numbers
- Average loop length
- Averages/Mean angle
- Averages/Mean time of day

### B

- Balanced brackets
- Balanced ternary
- Barnsley fern
- Bell numbers
- Benford's law
- Bernoulli numbers
- Best shuffle
- Bin given limits
- Binary search
- Bioinformatics/Sequence mutation
- Bioinformatics/base count
- Biorhythms
- Bitcoin/address validation
- Bitcoin/public point to address
- 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/Player
- Burrows–Wheeler transform

### C

- CSV data manipulation
- CSV to HTML translation
- CUSIP
- Calculating the value of e
- Calendar - for "REAL" programmers
- Calkin-Wilf sequence
- Canny edge detector
- Canonicalize CIDR
- Carmichael 3 strong pseudoprimes
- Cartesian product of two or more lists
- Casting out nines
- Catalan numbers
- Catalan numbers/Pascal's triangle
- Catamorphism
- 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
- Checkpoint synchronization
- Chernick's Carmichael numbers
- Cheryl's birthday
- Chinese remainder theorem
- Chinese zodiac
- Chowla numbers
- Church numerals
- Circles of given radius through two points
- Circular primes
- Cistercian numerals
- Color quantization
- Color wheel
- Colour bars/Display
- Colour pinstripe/Display
- Colour pinstripe/Printer
- Combinations and permutations
- Combinations with repetitions
- Comma quibbling
- Commatizing numbers
- Compare a list of strings
- Compare length of two strings
- Compare sorting algorithms' performance
- Compile-time calculation
- Compiler/AST interpreter
- Compiler/code generator
- Compiler/lexical analyzer
- Compiler/syntax analyzer
- Compiler/virtual machine interpreter
- Compound data type
- Concurrent computing
- Conjugate transpose
- Consecutive primes with ascending or descending differences
- Constrained genericity
- Constrained random points on a circle
- Continued fraction
- Continued fraction/Arithmetic/Construct from rational number
- Convert decimal number to rational
- Convert seconds to compound duration
- Convex hull
- Count in factors
- Count the coins
- Cramer's rule
- Create a file on magnetic tape
- Create an HTML table
- Create an object at a given address
- Cuban primes
- Currying
- Cut a rectangle
- Cyclotomic polynomial

### D

- DNS query
- Damm algorithm
- De Bruijn sequences
- Deal cards for FreeCell
- Death Star
- Deconvolution/1D
- Deconvolution/2D+
- Deepcopy
- Define a primitive data type
- Deming's Funnel
- Department numbers
- Determinant and permanent
- Determine if a string has all the same characters
- 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
- Digital root/Multiplicative digital root
- Dijkstra's algorithm
- Dinesman's multiple-dwelling problem
- Discordian date
- Display a linear combination
- Display an outline as a nested table
- Distributed programming
- Diversity prediction theorem
- 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
- Element-wise operations
- Elementary cellular automaton
- 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
- Equilibrium index
- Esthetic numbers
- Euler's constant 0.5772...
- Euler's identity
- Euler's sum of powers conjecture
- Events
- Executable library
- Execute Brain****
- Execute HQ9+
- Execute SNUSP
- Execute a Markov algorithm
- Extensible prime generator

### F

- FASTA format
- FTP
- Faces from a mesh
- Factorial base numbers indexing permutations of a collection
- Factorions
- Factors of a Mersenne number
- Fairshare between two and more
- Farey sequence
- Fast Fourier transform
- Faulhaber's formula
- Faulhaber's triangle
- Feigenbaum constant calculation
- Fermat numbers
- Fibonacci n-step number sequences
- Fibonacci word
- Fibonacci word/fractal
- File extension is in extensions list
- 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
- Find the missing permutation
- 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
- Five weekends
- Fivenum
- Fixed length records
- Flipping bits game
- Flow-control structures
- Floyd's triangle
- Floyd-Warshall algorithm
- Forest fire
- Formal power series
- Fortunate numbers
- Four bit adder
- Four is magic
- Four is the number of letters in the ...
- Fraction reduction
- Fractran
- French Republican calendar
- Function prototype
- Functional coverage tree
- Fusc sequence

### G

- GUI/Maximum window dimensions
- Galton box animation
- Gamma function
- Gapful numbers
- Gauss-Jordan matrix inversion
- Gaussian elimination
- General FizzBuzz
- Generate Chess960 starting position
- Generate random chess position
- Generator/Exponential
- Get system command output
- Globally replace text in several files
- Go Fish
- Graph colouring
- Gray code
- Grayscale image
- Greatest subsequential sum
- Greyscale bars/Display
- Guess the number

### H

- HTTPS
- HTTPS/Authenticated
- HTTPS/Client-authenticated
- Halt and catch fire
- Harshad or Niven series
- Hash join
- Haversine formula
- Here document
- Hickerson series of almost integers
- Hilbert curve
- Hofstadter-Conway $10,000 sequence
- Hofstadter Figure-Figure sequences
- Hofstadter Q sequence
- Holidays related to Easter
- Honeycombs
- Host introspection
- Hough transform
- Huffman coding
- Humble numbers
- Hunt the Wumpus

### I

- IBAN
- ISBN13 check digit
- I before E except after C
- Idiomatically determine all the characters that can be used for symbols
- Idiomatically determine all the lowercase and uppercase letters
- Image convolution
- Image noise
- Imaginary base numbers
- Increasing gaps between consecutive Niven numbers
- Index finite lists of positive integers
- Inheritance/Multiple
- Intersecting number wheels
- Inverted index
- Inverted syntax
- Isqrt (integer square root) of X
- Iterated digits squaring

### J

### K

- K-d tree
- K-means++ clustering
- Kaprekar numbers
- 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
- Koch curve
- Kolakoski sequence
- Kosaraju
- Kronecker product
- Kronecker product based fractals

### L

- LU decomposition
- LZW compression
- Lah numbers
- Langton's ant
- Largest number divisible by its digits
- Largest proper divisor of n
- Last letter-first letter
- Latin Squares in reduced form
- Latin Squares in reduced form/Randomizing using Jacobson and Matthews’ Technique
- Law of cosines - triples
- Left factorials
- Legendre prime counting function
- Leonardo numbers
- Levenshtein distance/Alignment
- Linear congruential generator
- List rooted trees
- Literals/String
- Long literals, with continuations
- Long primes
- Long year
- Longest common subsequence
- Longest common substring
- Longest increasing subsequence
- Longest string challenge
- Lucas-Lehmer test
- Lucky and even lucky numbers
- Ludic numbers
- Luhn test of credit card numbers
- Lychrel numbers

### M

- MAC Vendor Lookup
- MD4
- MD5/Implementation
- Mad Libs
- Magic 8-ball
- 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
- Mandelbrot set
- Map range
- Mastermind
- Matrix-exponentiation operator
- Matrix chain multiplication
- Matrix digital rain
- Matrix multiplication
- Matrix transposition
- Maximum triangle path sum
- Mayan calendar
- Mayan numerals
- Maze generation
- Maze solving
- McNuggets problem
- Median filter
- Memory layout of a data structure
- Menu
- Merge and aggregate datasets
- Mertens function
- Metallic ratios
- Metered concurrency
- Metronome
- Mian-Chowla sequence
- Middle three digits
- 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
- Modular arithmetic
- Modular exponentiation
- Modular inverse
- Monads/List monad
- Monads/Maybe monad
- Monads/Writer monad
- Monte Carlo methods
- Monty Hall problem
- Morse code
- Motzkin numbers
- Move-to-front algorithm
- Multi-dimensional array
- Multifactorial
- Multiple regression
- Multiplication tables
- Multiplicative order
- Multisplit
- Munchausen numbers
- Munching squares
- Musical scale
- Mutex
- Möbius function

### N

- N'th
- N-queens problem
- N-smooth numbers
- Naming conventions
- Narcissist
- Narcissistic decimal number
- Natural sorting
- Nautical bell
- Negative base numbers
- Nested function
- Nested templated data
- Next highest int from digits
- Nimber arithmetic
- Non-continuous subsequences
- Non-decimal radices/Input
- Non-transitive dice
- Nonoblock
- Nonogram solver
- Number names
- Number reversal game
- Numbers with equal rises and falls
- Numeric error propagation
- Numerical and alphabetical suffixes
- Numerical integration
- Numerical integration/Gauss-Legendre Quadrature

### O

- OLE automation
- Object serialization
- Odd word problem
- Old Russian measure of length
- Old lady swallowed a fly
- One-dimensional cellular automata
- One-time pad
- One of n lines in a file
- OpenGL
- OpenWebNet password
- Optional parameters
- Order by pair comparisons
- Order disjoint list items
- Order two numerical lists
- Ordered partitions

### 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
- Parametric polymorphism
- Parametrized SQL statement
- Parse an IP Address
- Parsing/RPN calculator algorithm
- Parsing/RPN to infix conversion
- Parsing/Shunting-yard algorithm
- Partition an integer x into n primes
- Partition function P
- Pascal's triangle
- Pascal's triangle/Puzzle
- Pascal matrix generation
- Password generator
- Pathological floating point problems
- 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
- Peripheral drift illusion
- Perlin noise
- Permutation test
- Permutations/Derangements
- Permutations/Rank of a permutation
- Permutations by swapping
- Pernicious numbers
- Pi
- 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
- Polynomial regression
- Polyspiral
- Population count
- Pragmatic directives
- Primality by Wilson's theorem
- Prime conspiracy
- Primes - allocate descendants to their ancestors
- Priority queue
- Probabilistic choice
- Problem of Apollonius
- Program termination
- Proper divisors
- Pseudo-random numbers/Combined recursive generator MRG32k3a
- Pseudo-random numbers/PCG32
- Pseudo-random numbers/Splitmix64
- Pseudo-random numbers/Xorshift star
- Pythagoras tree
- Pythagorean quadruples
- Pythagorean triples

### R

- RCRPG
- RIPEMD-160
- RPG attributes generator
- RSA code
- Ramanujan's constant
- Ramanujan primes/twins
- Ramer-Douglas-Peucker line simplification
- Random Latin squares
- Random number generator (device)
- Random number generator (included)
- Random numbers
- Random sentence from book
- Range consolidation
- Range expansion
- Range extraction
- Ranking methods
- Rare numbers
- Recaman's sequence
- Record sound
- Reduced row echelon form
- Reflection/Get source
- Reflection/List methods
- Reflection/List properties
- Remove lines from a file
- Rendezvous
- Rep-string
- Repeat
- Resistor mesh
- Rock-paper-scissors
- Roman numerals/Decode
- 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
- SHA-256 Merkle tree
- SQL-based authentication
- Safe addition
- Sailors, coconuts and a monkey problem
- Same fringe
- Scope/Function names and labels
- Scope modifiers
- Search a list of records
- Secure temporary file
- Self-describing numbers
- Self numbers
- Semiprime
- Semordnilap
- 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 primes by trial division
- Sequence of primorial primes
- Set consolidation
- Set of real numbers
- Set puzzle
- Seven-sided dice from five-sided dice
- Sexy primes
- Shell one-liner
- Shoelace formula for polygonal area
- Shortest common supersequence
- Show ASCII table
- Show the epoch
- Sierpinski arrowhead curve
- Sierpinski carpet
- Sierpinski pentagon
- Sierpinski square curve
- Sierpinski triangle
- Sierpinski triangle/Graphical
- Simple database
- Simulate input/Keyboard
- Simulate input/Mouse
- Singly-linked list/Element definition
- Singly-linked list/Element insertion
- Singly-linked list/Traversal
- Sleeping Beauty problem
- Smarandache prime-digital sequence
- Smith numbers
- Snake
- 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
- Sort numbers lexicographically
- Sort stability
- Sort three variables
- Sorting Algorithms/Circle Sort
- Sorting algorithms/Bead sort
- Sorting algorithms/Cocktail sort with shifting bounds
- Sorting algorithms/Comb sort
- Sorting algorithms/Heapsort
- Sorting algorithms/Insertion sort
- Sorting algorithms/Merge sort
- Sorting algorithms/Pancake sort
- Sorting algorithms/Patience sort
- Sorting algorithms/Permutation sort
- Sorting algorithms/Quicksort
- Sorting algorithms/Radix sort
- Sorting algorithms/Selection sort
- Sorting algorithms/Shell sort
- Sorting algorithms/Sleep sort
- Sorting algorithms/Strand sort
- Sparkline in unicode
- Special characters
- Speech synthesis
- Spelling of ordinal numbers
- Spinning rod animation/Text
- Spiral matrix
- Split a character string based on change of character
- Square-free integers
- Square but not cube
- Square form factorization
- Stable marriage problem
- Start from a main routine
- State name puzzle
- Statistics/Basic
- Statistics/Normal distribution
- Stem-and-leaf plot
- Stern-Brocot sequence
- Stirling numbers of the first kind
- Stirling numbers of the second kind
- Straddling checkerboard
- Strassen's algorithm
- Stream merge
- String append
- String interpolation (included)
- String prepend
- Strip block comments
- Strip comments from a string
- Strip control codes and extended characters from a string
- Strong and weak primes
- Subleq
- Substitution cipher
- Subtractive generator
- Successive prime differences
- Sudoku
- Suffixation of decimal numbers
- Sum and product puzzle
- Sum digits of an integer
- Sum multiples of 3 and 5
- 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
- Tau function
- Tau number
- Taxicab numbers
- Teacup rim text
- Temperature conversion
- 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
- Terminal control/Unicode output
- Ternary logic
- Test a function
- Test integerness
- 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
- Thue-Morse
- Tic-tac-toe
- Tokenize a string with escaping
- Tonelli-Shanks algorithm
- Top rank per group
- Topic variable
- Topological sort
- Topswops
- Total circles area
- Totient function
- Towers of Hanoi
- Trabb Pardo–Knuth algorithm
- Tree datastructures
- Tree from nesting levels
- Trigonometric functions
- Truncatable primes
- 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)
- Unbias a random generator
- Unicode strings
- Unicode variable names
- Universal Turing machine
- Unprimeable numbers
- Untouchable numbers
- Update a configuration file
- Use another language to call a function
- User input/Graphical

### V

- Validate International Securities Identification Number
- Vampire number
- Van Eck sequence
- Van der Corput sequence
- Variable-length quantity
- Variable size/Get
- Variable size/Set
- Variables
- Variadic function
- Vector
- Vector products
- Verhoeff algorithm
- Verify distribution uniformity/Chi-squared test
- Verify distribution uniformity/Naive
- Video display modes
- 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 Smalltalk (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
- Card shuffles
- Change e letters to i in words
- Changeable words
- Chebyshev coefficients
- Checksumcolor
- Chemical calculator
- Chess player
- Cipolla's algorithm
- 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
- Cycle detection
- Cyclops numbers

### D

- Data Encryption Standard
- Dating agency
- Days between dates
- Decimal floating point number to binary
- Decision tables
- Digit fifth powers
- Discrete Fourier transform
- Distinct Palindromes within decimal numbers
- Distinct power numbers
- Distribution of 0 Digits in factorial series
- Dominoes
- Doomsday rule
- Doubly-linked list/Element removal
- Draw pixel 2

### E

### F

- Fibonacci heap
- Fibonacci matrix-exponentiation
- Find URI in text
- Find adjacents primes which difference is 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 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
- 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 common suffix
- 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
- Mine a bitcoin
- Minimum number of cells after, before, above and below NxN squares
- Minimum numbers of three lists
- Minimum primes
- Montgomery reduction
- 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
- Parse EBNF
- Parse command-line arguments
- Particle fountain
- Particle swarm optimization
- Penrose tiling
- Pentomino 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 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
- 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
- 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
- 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
- Simple turtle graphics
- 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
- Snake and Ladder
- 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
- Starting a web browser
- 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 the digits of n is substring of n
- 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
- Triplet of three numbers
- Tropical algebra overloading
- Two identical strings
- Two sum

### U

### W

## Requiring Attention[edit]

### Examples[edit]

These tasks have implementations in Smalltalk, 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 Smalltalk which require attention; with your knowledge and assistance, we can improve the quality of the site's content.

## Not Considered[edit]

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

### P

## End of List[edit]

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