# Reports:Tasks not implemented in Swift

**Awareness**

If

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## Contents

## Not implemented[edit]

These are currently not implemented in Swift. Please implement some if you can. If any tasks are not possible or too complex in Swift, they should not be on this list. To mark a task as such, add **{{omit from|Swift}}**, 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
- Achilles numbers
- Active Directory/Connect
- Active Directory/Search for a user
- Almkvist-Giullera formula for pi
- Amb
- Anagrams/Deranged anagrams
- Animate a pendulum
- Animation
- 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 evaluation
- Arithmetic numbers
- Ascending primes
- Average loop length
- Averages/Median
- Averages/Pythagorean means

### B

- Balanced ternary
- Base64 decode data
- Best shuffle
- Bin given limits
- Binary strings
- 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
- Box the compass
- Brace expansion
- Brazilian numbers
- Brownian tree
- Bulls and cows/Player

### C

- CSV data manipulation
- CSV to HTML translation
- Calendar - for "REAL" programmers
- Calkin-Wilf sequence
- Call a function in a shared library
- Canny edge detector
- Canonicalize CIDR
- Cantor set
- Casting out nines
- Catalan numbers/Pascal's triangle
- 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
- Chinese zodiac
- Circular primes
- Cistercian numerals
- Collections
- Color of a screen pixel
- Color quantization
- Color wheel
- Colorful numbers
- Colour bars/Display
- Colour pinstripe/Display
- Colour pinstripe/Printer
- 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
- Composite numbers k with no single digit factors whose factors are all substrings of k
- Conditional structures
- Conjugate transpose
- Consecutive primes with ascending or descending differences
- Continued fraction/Arithmetic/Construct from rational number
- Convert decimal number to rational
- Copy stdin to stdout
- Cramer's rule
- Create a file
- Create a file on magnetic tape
- Create an HTML table
- Cuban primes
- Cullen and Woodall numbers
- Curzon numbers
- Cut a rectangle
- Cyclops numbers
- Cyclotomic polynomial

### D

- DNS query
- Damm algorithm
- De Bruijn sequences
- Death Star
- Deceptive numbers
- Deconvolution/2D+
- Deepcopy
- Delete a file
- Descending primes
- 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 two triangles overlap
- Determine sentence type
- Dice game probabilities
- Digital root
- Digital root/Multiplicative digital root
- Dinesman's multiple-dwelling problem
- Dining philosophers
- Disarium numbers
- Display a linear combination
- Display an outline as a nested table
- Distributed programming
- Diversity prediction theorem
- Dominoes
- Doubly-linked list/Traversal
- Dragon curve
- Draw a clock
- Draw a cuboid
- Draw a pixel
- Draw a rotating cube
- Duffinian numbers
- Dutch national flag problem

### E

- EKG sequence convergence
- Earliest difference between prime gaps
- Eban numbers
- Echo server
- Eertree
- 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
- Entropy/Narcissist
- Equal prime and composite sums
- Erdös-Selfridge categorization of primes
- Euler's constant 0.5772...
- Euler's identity
- Events
- Executable library
- Execute Computer/Zero
- Execute HQ9+
- Execute SNUSP
- Execute a system command
- Exponentiation with infix operators in (or operating on) the base
- Extend your language

### F

- FASTA format
- FTP
- Faces from a mesh
- Factorial base numbers indexing permutations of a collection
- Fairshare between two and more
- Faulhaber's formula
- Faulhaber's triangle
- Fermat numbers
- Fibonacci n-step number sequences
- Fibonacci word/fractal
- File extension is in extensions list
- File input/output
- File modification time
- File size
- File size distribution
- Find Chess960 starting position identifier
- Find duplicate files
- Find if a point is within a triangle
- Find the intersection of a line with a plane
- Find the missing permutation
- First-class functions/Use numbers analogously
- First class environments
- First perfect square in base n with n unique digits
- Five weekends
- Fivenum
- Fixed length records
- Flow-control structures
- Floyd's triangle
- Floyd-Warshall algorithm
- Forest fire
- Fork
- Formal power series
- Formatted numeric output
- Fortunate numbers
- Four is the number of letters in the ...
- Fraction reduction
- Fractran
- French Republican calendar
- Function frequency

### G

- GUI/Maximum window dimensions
- GUI component interaction
- GUI enabling/disabling of controls
- Galton box animation
- Gamma function
- Gauss-Jordan matrix inversion
- Generate random chess position
- Globally replace text in several files
- Go Fish
- Goldbach's comet
- Graph colouring
- Grayscale image
- Greyscale bars/Display

### H

- HTTPS/Authenticated
- HTTPS/Client-authenticated
- Hamming numbers
- Harmonic series
- Hello world/Web server
- Here document
- Hickerson series of almost integers
- Hilbert curve
- Hofstadter Figure-Figure sequences
- Holidays related to Easter
- Home primes
- Honeycombs
- Horizontal sundial calculations
- Host introspection
- Hough transform
- Humble numbers

### I

- IBAN
- 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
- Include a file
- Increasing gaps between consecutive Niven numbers
- Index finite lists of positive integers
- Input loop
- Interactive programming (repl)
- Intersecting number wheels
- Introspection
- Inverted index

### K

- K-d tree
- K-means++ clustering
- Kaprekar numbers
- Keyboard input/Flush the keyboard buffer
- Keyboard input/Keypress check
- Keyboard input/Obtain a Y or N response
- Keyboard macros
- Knapsack problem/Continuous
- Knapsack problem/Unbounded
- Knuth's power tree
- Koch curve
- Kolakoski sequence
- Kronecker product based fractals

### L

- LU decomposition
- Largest int from concatenated ints
- Largest number divisible by its digits
- Last letter-first letter
- 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 multiplication
- Longest string challenge
- Loops/Increment loop index within loop body
- Loops/With multiple ranges
- Loops/Wrong ranges
- Ludic numbers

### M

- MAC vendor lookup
- MD4
- MD5
- Mad Libs
- Magic 8-ball
- Magic constant
- Magic squares of doubly even order
- Magic squares of singly even order
- Main step of GOST 28147-89
- Make directory path
- Mastermind
- Matrix-exponentiation operator
- Matrix chain multiplication
- Matrix digital rain
- Maximum triangle path sum
- Mayan calendar
- Mayan numerals
- Median filter
- Memory allocation
- Memory layout of a data structure
- Merge and aggregate datasets
- Metallic ratios
- Metaprogramming
- Metered concurrency
- Metronome
- Mind boggling card trick
- Minesweeper game
- Minimum positive multiple in base 10 using only 0 and 1
- Minkowski question-mark function
- Modified random distribution
- Monads/List monad
- Monads/Maybe monad
- Monads/Writer monad
- Morse code
- Mouse position
- Multi-base primes
- Multi-dimensional array
- Multiple regression
- Multiplicative order
- Munching squares
- Musical scale
- Mutex
- Möbius function

### N

- Naming conventions
- Natural sorting
- Nautical bell
- Negative base numbers
- Nested templated data
- Next highest int from digits
- Non-continuous subsequences
- Non-decimal radices/Input
- Non-decimal radices/Output
- Non-transitive dice
- Nonogram solver
- Number reversal game
- Numbers which are not the sum of distinct squares
- Numerical and alphabetical suffixes
- Numerical integration/Gauss-Legendre Quadrature

### O

### P

- P-Adic numbers, basic
- P-Adic square roots
- P-value correction
- Padovan n-step number sequences
- Palindromic gapful numbers
- Pancake numbers
- Paraffins
- Parameterized SQL statement
- Parse an IP Address
- Parsing/RPN to infix conversion
- Partial function application
- Particle fountain
- Pascal's triangle/Puzzle
- Pascal matrix generation
- Peano curve
- Pell numbers
- Penney's game
- Pentagram
- Pentomino tiling
- Percolation/Mean cluster density
- Percolation/Mean run density
- Percolation/Site percolation
- Periodic table
- Peripheral drift illusion
- Permutation test
- Permutations/Derangements
- Permutations/Rank of a permutation
- Pig the dice game
- Pig the dice game/Player
- Pinstripe/Display
- Pinstripe/Printer
- Pisano period
- Plasma effect
- Playfair cipher
- Plot coordinate pairs
- Pointers and references
- Poker hand analyser
- Polyspiral
- Pragmatic directives
- Prime conspiracy
- Primes - allocate descendants to their ancestors
- Primorial numbers
- Probabilistic choice
- Program name
- Program termination
- Pseudo-random numbers/Combined recursive generator MRG32k3a
- Pseudo-random numbers/Middle-square method
- Pseudo-random numbers/PCG32
- Pseudo-random numbers/Splitmix64
- Pythagoras tree

### R

- RCRPG
- RPG attributes generator
- RSA code
- Ramanujan's constant
- Ramanujan primes/twins
- Random Latin squares
- Random number generator (device)
- Random number generator (included)
- Random numbers
- Random sentence from book
- Range consolidation
- Range expansion
- Ranking methods
- Rare numbers
- Rate counter
- Ray-casting algorithm
- Read a configuration file
- Read a file character by character/UTF8
- Read a file line by line
- Read a specific line from a file
- Recaman's sequence
- Record sound
- Reflection/Get source
- Reflection/List methods
- Reflection/List properties
- Remove lines from a file
- Rename a file
- Rendezvous
- Repunit primes
- Resistor mesh
- Retrieve and search chat history
- 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
- Runtime evaluation/In an environment
- Ruth-Aaron numbers

### S

- S-expressions
- SEDOLs
- SHA-1
- SHA-256
- SHA-256 Merkle tree
- SOAP
- SQL-based authentication
- Sailors, coconuts and a monkey problem
- Same fringe
- Scope/Function names and labels
- Scope modifiers
- Search in paragraph's text
- Secure temporary file
- Selectively replace multiple instances of a character within a string
- Self numbers
- Send email
- Sequence: nth number with exactly n divisors
- Sequence of non-squares
- Set consolidation
- Set of real numbers
- Set puzzle
- Set right-adjacent bits
- Seven-sided dice from five-sided dice
- Sexy primes
- Shell one-liner
- Shortest common supersequence
- Show ASCII table
- Show the epoch
- Sierpinski arrowhead curve
- Sierpinski pentagon
- Sierpinski square curve
- Sierpinski triangle/Graphical
- Simple database
- Simple turtle graphics
- Simple windowed application
- Simulate input/Keyboard
- Simulate input/Mouse
- Singly-linked list/Element insertion
- Singly-linked list/Traversal
- Smallest number k such that k+2^m is composite for all m less than k
- Snake
- Sockets
- 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 an outline at every level
- Sort stability
- Sorting algorithms/Bead sort
- Sorting algorithms/Counting sort
- Sorting algorithms/Patience sort
- Sorting algorithms/Permutation sort
- Sorting algorithms/Radix sort
- Sorting algorithms/Strand sort
- Soundex
- Sparkline in unicode
- Special characters
- Special variables
- Spinning rod animation/Text
- Spiral matrix
- Square form factorization
- Stack traces
- State name puzzle
- Statistics/Basic
- Statistics/Normal distribution
- Stem-and-leaf plot
- Stirling numbers of the first kind
- Stirling numbers of the second kind
- Straddling checkerboard
- Stream merge
- Strip comments from a string
- Strip control codes and extended characters from a string
- Strip whitespace from a string/Top and tail
- Substitution cipher
- Subtractive generator
- 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 and say sequence
- Summarize primes
- Superellipse
- Superpermutation minimisation

### T

- Table creation/Postal addresses
- Tarjan
- Terminal control/Clear the screen
- 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/Ringing the terminal bell
- Terminal control/Unicode output
- Ternary logic
- Test integerness
- Text processing/2
- Text processing/Max licenses in use
- The Name Game
- The sieve of Sundaram
- Thue-Morse
- Tonelli-Shanks algorithm
- Topic variable
- Topswops
- Total circles area
- Totient function
- Tree datastructures
- Tree from nesting levels
- Trigonometric functions
- Truncate a file
- Truth table
- Twelve statements
- Twin primes
- Two's complement
- Two bullet roulette

### U

### V

- Validate International Securities Identification Number
- Variable-length quantity
- Variable declaration reset
- Variable size/Set
- 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

- Walk a directory/Non-recursively
- War card game
- Web scraping
- Weird numbers
- Wilson primes of order n
- Window creation
- Window creation/X11
- Window management
- Wireworld
- Word search
- Word wheel
- Word wrap
- Wordiff
- World Cup group stage
- Write entire file
- Write float arrays to a text file
- Write language name in 3D ASCII
- Write to Windows event log

### 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 Swift (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
- ADFGVX cipher
- Addition-chain exponentiation
- Addition chains
- 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
- Base58Check encoding
- Base64 encode data
- 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
- Card shuffles
- 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/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
- Create an executable for a program in an interpreted language
- Create an object/Native demonstration
- Create your own text control codes
- Cross compilation
- Cubic special primes
- Curve that touches three points
- Cycle detection
- 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
- Decision tables
- 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
- Doomsday rule
- Doubly-linked list/Element removal
- Draw pixel 2

### E

### F

- Factorial primes
- Fermat pseudoprimes
- 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 square difference
- Find squares n where n+1 is prime
- Find words which contain the most 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
- Length of an arc between two angles
- 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
- Marching squares
- Matrix with two diagonals
- Maximum difference between adjacent elements of list
- Mersenne primes
- 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-queens minimum and knights and bishops
- NYSIIS
- Names to numbers
- 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 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
- Parse EBNF
- Parse command-line arguments
- Particle swarm optimization
- Penrose tiling
- Perceptron
- Permutations with repetitions
- Permutations with some identical elements
- 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
- 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
- Pseudorandom number generator image

### R

- Ramanujan primes
- Ramsey's theorem
- Range modifications
- Raster bars
- Readline interface
- Recursive descent parser generator
- Red black tree sort
- 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
- Snake and ladder
- 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 factorials
- Special neighbor primes
- Special pythagorean triplet
- Spoof game
- Square root by hand
- Starting a web browser
- Steady squares
- Strange numbers
- Strange plus numbers
- 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
- Super-Poulet numbers

### 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
- The ISAAC cipher
- Three word location
- Time-based one-time password algorithm
- Topological sort/Extracted top item
- Transliterate English text using the Greek alphabet
- Transportation problem
- Triplet of three numbers
- Tropical algebra overloading
- Two sum
- Type detection

### U

### W

## Requiring Attention[edit]

### Examples[edit]

These tasks have implementations in Swift, 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 Swift 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 Swift 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.