Tasks not implemented in R
Awareness
If R is a language you like, or are interested in, please inform your fellow members of the R community; this page can't be emptied without your and their participation.
If R is a language you like, or are interested in, please inform your fellow members of the R community; this page can't be emptied without your and their participation.
Tasks not implemented in R
1
A
- ADFGVX cipher
- ASCII art diagram converter
- AVL tree
- Abbreviations, simple
- Abelian sandpile model/Identity
- Abstract type
- Achilles numbers
- Active Directory/Connect
- Active Directory/Search for a user
- Active object
- Algebraic data types
- Aliquot sequence classifications
- Almkvist-Giullera formula for pi
- Anadromes
- Anagram generator
- Angle difference between two bearings
- Angles (geometric), normalization and conversion
- Append a record to the end of a text file
- Apply a digital filter (direct form II transposed)
- Arena storage pool
- Arithmetic derivative
- Arithmetic evaluation
- Arithmetic numbers
- Arithmetic/Rational
- Ascending primes
- Associative array/Merging
- Atomic updates
- Averages/Mean time of day
B
- Babylonian spiral
- Balanced ternary
- Bell numbers
- Bernstein basis polynomials
- Best shuffle
- Bifid cipher
- Binary strings
- Bioinformatics/Global alignment
- Bioinformatics/Sequence mutation
- Bitcoin/address validation
- Bitcoin/public point to address
- Bitmap/Bresenham's line algorithm
- Bitmap/Histogram
- Bitmap/Midpoint circle algorithm
- Bitmap/PPM conversion through a pipe
- Bitmap/Read a PPM file
- Bitmap/Read an image through a pipe
- Bitwise IO
- Blum integer
- Boustrophedon transform
- Boyer-Moore string search
- Brace expansion
- Brazilian numbers
- Brilliant numbers
- Burrows–Wheeler transform
- Bézier curves/Intersections
C
- CUSIP
- Calendar - for "REAL" programmers
- Calkin-Wilf sequence
- Call a foreign-language function
- Call an object method
- Camel case and snake case
- Canny edge detector
- Canonicalize CIDR
- Carmichael 3 strong pseudoprimes
- Catalan numbers/Pascal's triangle
- Catmull–Clark subdivision surface
- Centre and radius of a circle passing through 3 points in a plane
- Chaocipher
- Check if a polygon overlaps with a rectangle
- Check if two polygons overlap
- Check input device is a terminal
- Check output device is a terminal
- Checkpoint synchronization
- Chernick's Carmichael numbers
- Chinese zodiac
- Chowla numbers
- Circles of given radius through two points
- Circular primes
- Cistercian numerals
- Color quantization
- Color wheel
- Colorful numbers
- Colour pinstripe/Display
- Colour pinstripe/Printer
- Commatizing numbers
- 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
- Concurrent computing
- Conjugate transpose
- Consecutive primes with ascending or descending differences
- Constrained genericity
- Continued fraction
- Continued fraction/Arithmetic/Construct from rational number
- Continued fraction/Arithmetic/G(matrix ng, continued fraction n)
- Continued fraction/Arithmetic/G(matrix ng, continued fraction n1, continued fraction n2)
- Convert seconds to compound duration
- Convex hull
- Count in octal
- 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
- Cullen and Woodall numbers
- Currency
- Curzon numbers
- Cut a rectangle
- Cycles of a permutation
- Cyclops numbers
- Cyclotomic polynomial
D
- De Bruijn sequences
- De Polignac numbers
- Death Star
- Deceptive numbers
- Deconvolution/2D+
- Decorate-sort-undecorate idiom
- Deepcopy
- Define a primitive data type
- Delegates
- Deming's funnel
- Descending primes
- Determine if only one instance is running
- Determine if two triangles overlap
- Determine sentence type
- Digital root/Multiplicative digital root
- Dijkstra's algorithm
- Dining philosophers
- Disarium numbers
- Discordian date
- Display a linear combination
- Display an outline as a nested table
- Distance and Bearing
- Distributed programming
- Distribution of 0 digits in factorial series
- Dominoes
- Doomsday rule
- 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
- Draw a sphere
- Duffinian numbers
- Dutch national flag problem
E
- EKG sequence convergence
- Earliest difference between prime gaps
- Eban numbers
- Echo server
- Eertree
- Elementary cellular automaton
- Elementary cellular automaton/Infinite length
- Elementary cellular automaton/Random number generator
- Elliptic Curve Digital Signature Algorithm
- Elliptic curve arithmetic
- Enforced immutability
- Entropy/Narcissist
- Equal prime and composite sums
- Equilibrium index
- Erdös-Selfridge categorization of primes
- Erdős-Nicolas numbers
- Esthetic numbers
- Euclid-Mullin sequence
- Euler's constant 0.5772...
- Euler's sum of powers conjecture
- Events
- Execute Computer/Zero
- Execute HQ9+
- Execute SNUSP
- Execute a Markov algorithm
- Extensible prime generator
F
- FTP
- Faces from a mesh
- Factorial base numbers indexing permutations of a collection
- Factorial primes
- Factorions
- Factorize string into Lyndon words
- Factors of a Mersenne number
- Fairshare between two and more
- Faulhaber's formula
- Faulhaber's triangle
- Feigenbaum constant calculation
- Fermat numbers
- Fermat pseudoprimes
- Fibonacci n-step number sequences
- File extension is in extensions list
- File size distribution
- Find Chess960 starting position identifier
- 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 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
- Flow-control structures
- Floyd-Warshall algorithm
- Forest fire
- Formal power series
- Fortunate numbers
- Four bit adder
- Four is the number of letters in the ...
- Fraction reduction
- Fractran
- French Republican calendar
- Function frequency
- Functional coverage tree
G
- GSTrans string conversion
- GUI/Maximum window dimensions
- Galton box animation
- Gapful numbers
- Gauss-Jordan matrix inversion
- Gaussian primes
- Giuga numbers
- Globally replace text in several files
- Go Fish
- Goldbach's comet
- Golden ratio/Convergence
- Gotchas
- Graph colouring
- Greatest prime dividing the n-th cubefree number
- Greedy algorithm for Egyptian fractions
H
- HTTPS/Authenticated
- HTTPS/Client-authenticated
- Halt and catch fire
- Handle a signal
- Harshad or Niven series
- Hash join
- Hello world/Line printer
- Hello world/Newbie
- Here document
- Hex words
- Hickerson series of almost integers
- Hilbert curve
- History variables
- Home primes
- Honaker primes
- Honeycombs
- Horizontal sundial calculations
- Hough transform
- Huffman coding
- Humble numbers
- Hunt the Wumpus
I
- I'm a software engineer, get me out of here
- IBAN
- ISBN13 check digit
- Idiomatically determine all the characters that can be used for symbols
- Idoneal numbers
- Image convolution
- Image noise
- Imaginary base numbers
- Inconsummate numbers in base 10
- Increasing gaps between consecutive Niven numbers
- Index finite lists of positive integers
- Inheritance/Multiple
- Integer overflow
- Intersecting number wheels
- Inverted index
- Isograms and heterograms
- Isqrt (integer square root) of X
- Iterated digits squaring
J
- Jacobi symbol
- Jacobsthal numbers
- Jaro similarity
- Jaro-Winkler distance
- Jordan-Pólya numbers
- JortSort
- Juggler sequence
- Julia set
- Jump anywhere
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
- Klarner-Rado sequence
- Knuth's algorithm S
- Knuth's power tree
- Koch curve
- Kolakoski sequence
- Kosaraju
L
- LZW compression
- Last letter-first letter
- Latin Squares in reduced form
- Legendre prime counting function
- Levenshtein distance
- Levenshtein distance/Alignment
- List rooted trees
- Literals/Floating point
- Long literals, with continuations
- Long primes
- Long year
- Longest common subsequence
- Longest common substring
- Longest increasing subsequence
- Longest string challenge
- Loops/With multiple ranges
- Lucky and even lucky numbers
- Ludic numbers
- Lyndon word
M
- MAC vendor lookup
- MD4
- MD5/Implementation
- Machine code
- Mad Libs
- Magic constant
- Magnanimous numbers
- Main step of GOST 28147-89
- Make directory path
- Mastermind
- Matrix digital rain
- Maximum triangle path sum
- Mayan calendar
- Mayan numerals
- Maze generation
- Maze solving
- Median filter
- Meissel–Mertens constant
- Memory layout of a data structure
- Mertens function
- Metallic ratios
- Metered concurrency
- Metronome
- Mian-Chowla sequence
- Middle three digits
- Miller–Rabin primality test
- Minesweeper game
- 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
- Modular arithmetic
- Modular exponentiation
- Modular inverse
- Monads/List monad
- Monads/Maybe monad
- Monads/Writer monad
- Morse code
- Motzkin numbers
- Move-to-front algorithm
- Multi-base primes
- Multi-dimensional array
- Multiplicative order
- Multisplit
- Munchausen numbers
- Munching squares
- Mutex
- Möbius function
N
- N-smooth numbers
- Naming conventions
- Narcissist
- Natural sorting
- Nautical bell
- Negative base numbers
- Next highest int from digits
- Nonoblock
- Nonogram solver
- Numbers k such that the last letter of k is the same as the first letter of k+1
- Numbers which are not the sum of distinct squares
- Numbers which are the cube roots of the product of their proper divisors
- Numbers with equal rises and falls
- Numeric error propagation
- Numerical and alphabetical suffixes
- Numerical integration/Gauss-Legendre Quadrature
O
- OLE automation
- Object serialization
- Odd word problem
- Old Russian measure of length
- One-time pad
- OpenWebNet password
- Operator precedence
- Order by pair comparisons
- Order disjoint list items
- Order two numerical lists
- Ordered partitions
- Ormiston triples
- Own digits power sum
P
- P-Adic numbers, basic
- P-Adic square roots
- Padovan n-step number sequences
- Pairs with common factors
- Palindrome dates
- Palindromic gapful numbers
- Pan base non-primes
- Pancake numbers
- Paraffins
- Parallel brute force
- Parallel calculations
- Parameterized SQL statement
- Parametric polymorphism
- Parse an IP Address
- Parsing/RPN calculator algorithm
- Parsing/RPN to infix conversion
- Parsing/Shunting-yard algorithm
- Particle fountain
- Partition an integer x into n primes
- Partition function P
- Pascal's triangle/Puzzle
- Pathological floating point problems
- Peaceful chess queen armies
- Pell numbers
- Pell's equation
- Penta-power prime seeds
- Pentomino tiling
- Percentage difference between images
- Percolation/Bond percolation
- Percolation/Mean cluster density
- Percolation/Mean run density
- Percolation/Site percolation
- Perfect totient numbers
- Periodic table
- Peripheral drift illusion
- Perlin noise
- Permutations by swapping
- Permutations/Derangements
- Permutations/Rank of a permutation
- Pernicious numbers
- Phrase reversals
- Pierpont primes
- Pig the dice game
- Pig the dice game/Player
- Pinstripe/Display
- Pinstripe/Printer
- Pisano period
- Plasma effect
- Playfair cipher
- Pointers and references
- Poker hand analyser
- Polymorphic copy
- Polyspiral
- Pragmatic directives
- Primality by Wilson's theorem
- Prime numbers whose neighboring pairs are tetraprimes
- Prime triangle
- Primes - allocate descendants to their ancestors
- Primes: n*2^m+1
- Primorial numbers
- Problem of Apollonius
- Product of min and max prime factors
- Pseudo-random numbers/Combined recursive generator MRG32k3a
- Pseudo-random numbers/Middle-square method
- Pseudo-random numbers/PCG32
- Pseudo-random numbers/Splitmix64
- Pseudo-random numbers/Xorshift star
- Pythagorean triples
Q
R
- RCRPG
- RIPEMD-160
- RSA code
- Radical of an integer
- Ramanujan primes/twins
- Ramanujan's constant
- Ramer-Douglas-Peucker line simplification
- Random Latin squares
- Random number generator (device)
- Random sentence from book
- Range consolidation
- Ranking methods
- Rare numbers
- Rate counter
- Read a configuration file
- Read a file character by character/UTF8
- Record sound
- Reflection/Get source
- Reflection/List methods
- Reflection/List properties
- Remove lines from a file
- Rename a file
- Rendezvous
- Rep-string
- Repunit primes
- Resistor mesh
- Respond to an unknown method call
- Retrieve and search chat history
- Rhonda numbers
- Riordan numbers
- Rosetta Code/Find bare lang tags
- Rosetta Code/Rank languages by number of users
- Round-robin tournament schedule
- Ruth-Aaron numbers
S
- S-expressions
- SHA-256 Merkle tree
- SOAP
- SQL-based authentication
- Safe addition
- Safe primes and unsafe primes
- Same fringe
- Scope/Function names and labels
- Search a list of records
- Search in paragraph's text
- Secure temporary file
- Selectively replace multiple instances of a character within a string
- Self numbers
- Self-describing numbers
- Semiprime
- Semordnilap
- Send an unknown method call
- Sequence of primes by trial division
- Sequence of primorial primes
- Sequence: nth number with exactly n divisors
- Set
- Set consolidation
- Set of real numbers
- Set puzzle
- Set right-adjacent bits
- Set, the card game
- Sexy primes
- Shoelace formula for polygonal area
- Shortest common supersequence
- Sierpinski arrowhead curve
- Sierpinski pentagon
- Sierpinski square curve
- Sieve of Pritchard
- Simple database
- Simple turtle graphics
- Singleton
- Singly-linked list/Element definition
- Singly-linked list/Element insertion
- Singly-linked list/Traversal
- Singular value decomposition
- Sisyphus sequence
- Smallest number k such that k+2^m is composite for all m less than k
- Smarandache prime-digital sequence
- Smarandache-Wellin primes
- Smith numbers
- Snake
- Sokoban
- Soloway's recurring rainfall
- Solve a Hidato puzzle
- Solve a Holy Knight's tour
- Solve a Hopido puzzle
- Solve a Numbrix puzzle
- Solve the no connection puzzle
- Sorensen–Dice coefficient
- Sort a list of object identifiers
- Sort an outline at every level
- Sort numbers lexicographically
- Sorting Algorithms/Circle Sort
- Sorting algorithms/Bead sort
- Sorting algorithms/Cocktail sort with shifting bounds
- Sorting algorithms/Heapsort
- Sorting algorithms/Pancake sort
- Sorting algorithms/Patience sort
- Sorting algorithms/Radix sort
- Sorting algorithms/Shell sort
- Sorting algorithms/Sleep sort
- Sorting algorithms/Strand sort
- Soundex
- Special characters
- Special variables
- Speech synthesis
- Spelling of ordinal numbers
- Sphenic numbers
- Spinning rod animation/Text
- Split a character string based on change of character
- Square but not cube
- Square form factorization
- Square-free integers
- Stable marriage problem
- Start from a main routine
- State name puzzle
- Steffensen's method
- 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 matching
- String prepend
- Strip a set of characters from a string
- Strip block comments
- Strip control codes and extended characters from a string
- Strong and weak primes
- Sub-unit squares
- Substitution cipher
- Substring/Top and tail
- Subtractive generator
- Successive prime differences
- Sudoku
- Suffixation of decimal numbers
- Sum and product puzzle
- Sum to 100
- Summarize and say sequence
- Summarize primes
- Super-Poulet numbers
- Superellipse
- Superpermutation minimisation
- Sutherland-Hodgman polygon clipping
- Sylvester's sequence
- Synchronous concurrency
T
- Table creation/Postal addresses
- Tarjan
- Taxicab numbers
- Teacup rim text
- Terminal control/Coloured text
- Terminal control/Cursor movement
- Terminal control/Cursor positioning
- Terminal control/Dimensions
- Terminal control/Inverse video
- Terminal control/Positional read
- Ternary logic
- Test integerness
- Textonyms
- The Name Game
- The sieve of Sundaram
- Thiele's interpolation formula
- Tokenize a string with escaping
- Tonelli-Shanks algorithm
- Topic variable
- Total circles area
- Totient function
- Transliterate English text using the Greek alphabet
- Tree datastructures
- Tree from nesting levels
- Tree traversal
- Truncatable primes
- Tupper's self-referential formula
- Twelve statements
- Twin primes
- Two bullet roulette
- Two's complement
U
- UPC
- UTF-8 encode and decode
- Ukkonen’s suffix tree construction
- Ultra useful primes
- Undulating numbers
- Unicode strings
- Universal Lambda Machine
- Universal Turing machine
- Unprimeable numbers
- Untouchable numbers
- Update a configuration file
- Use another language to call a function
V
- Validate International Securities Identification Number
- Vampire number
- Van Eck sequence
- Van der Corput sequence
- Variable declaration reset
- Variable size/Set
- Variable-length quantity
- Variadic fixed-point combinator
- Vector
- Verhoeff algorithm
- Video display modes
- Vigenère cipher/Cryptanalysis
- Visualize a tree
- Vogel's approximation method
W
- Wagstaff primes
- War card game
- Wasteful, equidigital and frugal numbers
- Water collected between towers
- Weird numbers
- Wieferich primes
- Wilson primes of order n
- Window creation/X11
- Window management
- Wireworld
- Word ladder
- Word search
- Word wheel
- Wordiff
- Wordle comparison
- World Cup group stage
- Write entire file
- Write language name in 3D ASCII
- Write to Windows event log
X
Y
Z
Draft tasks not implemented in R
1
3
A
- A* search algorithm
- ASCII control characters
- Addition chains
- Addition-chain exponentiation
- Air mass
- Alternade words
- Anaprimes
- Append numbers at same position in strings
- Apéry's constant
- Arithmetic coding/As a generalized change of radix
- Aspect oriented programming
- Assertions in design by contract
- Audio alarm
- Audio frequency generator
- Audio overlap loop
- Autogram checker
B
- B-spline
- Bacon cipher
- Banker's algorithm
- Base 16 numbers needing a to f
- Base58Check encoding
- Base64 encode data
- Bilinear interpolation
- Binary coded decimal
- Binomial transform
- Bioinformatics/Subsequence
- Birthday problem
- Black box
- Blackjack strategy
- Boids
- Brace expansion using ranges
C
- CLI-based maze-game
- CORDIC
- Calmo numbers
- CalmoSoft primes
- Card shuffles
- Carmichael lambda function
- Centroid of a set of N-dimensional points
- Changeable words
- Chebyshev coefficients
- Checksumcolor
- Chemical calculator
- Chess player
- Cipolla's algorithm
- Code segment unload
- Collect and sort square numbers in ascending order from three lists
- Color separation
- 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
- Consistent overhead byte stuffing
- Continued fraction convergents
- Convert CSV records to TSV
- Coprime triplets
- Count how many vowels and consonants occur in a string
- Count the coins/0-1
- Countdown
- Cousin primes
- 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
D
- Data Encryption Standard
- Dating agency
- Day of the week of Christmas and New Year
- Days between dates
- Decimal floating point number to binary
- Decision tables
- Digit fifth powers
- Diophantine linear system solving
- Discrete Fourier transform
- Distinct palindromes within decimal numbers
- Divide a rectangle into a number of unequal triangles
- Double Twin Primes
- Doubly-linked list/Element removal
- Draw pixel 2
E
- Eisenstein primes
- Elevator simulation
- Engel expansion
- English cardinal anagrams
- Erdős-primes
- Erdős–Woods numbers
- Even numbers which cannot be expressed as the sum of two twin primes
- Exactly three adjacent 3 in lists
- Execute CopyPasta Language
- Exponential digital sums
- Extended Straddling Checkerboard
- External sort
- Extra primes
- Extract file extension
- Extreme primes
F
- Factor-perfect numbers
- 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 with alternating vowels and consonants
- Finite state machine
- First 9 prime Fibonacci number
- Forbidden numbers
- Four sides of square
- Free polyominoes enumeration
- Frobenius numbers
G
- Generalised floating point addition
- Generalised floating point multiplication
- Geohash
- Geometric algebra
- Getting the number of decimal places
- Goodstein Sequence
- Gradient descent
- Greed
H
I
- IPC via named pipe
- IRC gateway
- Iccanobif primes
- Implicit type conversion
- Inner classes
- Input/Output for lines of text
- Input/Output for pairs of numbers
- Integer long division
- Integer roots
- Interactive help
- Inventory sequence
- Iterators
J
K
L
- L-system
- Lagrange Interpolation
- Largest difference between adjacent primes
- Largest five adjacent number
- Largest palindrome product
- Largest product in a grid
- Last list item
- Latin Squares in reduced form/Randomizing using Jacobson and Matthews' technique
- Launch rocket with countdown and acceleration in stdout
- Least m such that n! + m is prime
- Length of an arc between two angles
- Line circle intersection
- Linux CPU utilization
- Long stairs
- Longest common prefix
- Longest common suffix
- Longest palindromic substrings
- Longest substrings without repeating characters
- Lucas-Carmichael numbers
M
- Magic numbers
- Make a backup file
- Marching squares
- Markov chain text generator
- 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
- Multiplicatively perfect numbers
- Multiton
N
- N-body problem
- N-grams
- 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 10 that are palindromic in bases 2, 4, and 16
- Numbers in base-16 representation that cannot be written with decimal digits
- Numbers whose binary and ternary digit sums 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
- Odd and square numbers
- Odd squarefree semiprimes
- Odd words
- One-two primes
- OpenGL pixel shader
- OpenGL/Utah teapot
- Orbital elements
- Ormiston pairs
- Overloaded operators
P
- Palindromic primes
- Palindromic primes in base 16
- Pandigital prime
- Parse EBNF
- Parse command-line arguments
- Particle swarm optimization
- Penholodigital squares
- Penrose tiling
- Perceptron
- Permutations with repetitions
- Permutations with some identical elements
- Permuted multiples
- Piprimes
- Polynomial derivative
- Polynomial synthetic division
- Posit numbers/decoding
- Posit numbers/encoding
- 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 reciprocal sum
- 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
- Proof
- Protecting Memory Secrets
- Pseudorandom number generator image
Q
R
- Railway circuit
- Rainbow
- 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
- Remove vowels from a string
- Resistance calculator
- Resistance network calculator
- Reverse the gender of a string
- Rice coding
- Robots
- Rodrigues’ rotation formula
- Roots of a cubic polynomial
- Rosetta Code/List authors of task descriptions
- Rosetta Code/Run examples
- Rosetta Code/Tasks without examples
- Run as a daemon or service
S
- SEND + MORE = MONEY
- Safe and Sophie Germain primes
- Safe mode
- Sanitize user input
- Sealed classes and methods
- Segmentation fault protection
- Selection bias in clinical sciences
- 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
- Simulated optics experiment/Data analysis
- Simulated optics experiment/Simulator
- Sine wave
- Singly-linked list/Element removal
- Singly-linked list/Reversal
- 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 solitaire 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
- Statistics/Chi-squared distribution
- Steady squares
- Strange numbers
- Strange unique prime triplets
- Sturmian word
- Subset sum problem
- Substring primes
- Suffix tree
- Sum data type
- 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
- Syntax highlighting using Mediawiki formatting
- Szymański's algorithm
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
- The ISAAC cipher
- Three word location
- Time-based one-time password algorithm
- Topological sort/Extracted top item
- Triangular numbers
- Triplet of three numbers
- Two identical strings
- Two sum
- Type detection
U
- URL shortener
- Ulam numbers
- Unicode polynomial equation
- Unique characters
- Unique characters in each string
- Unit testing
- Uno (card game)
- Untrusted environment
- Upside-down numbers
- Use a REST API
- Useless instructions
- User defined pipe and redirection operators
- Using a speech engine to highlight words
V
W
- Walsh matrix
- Wave function collapse
- Waveform analysis/Doh ray me
- Waveform analysis/Top and tail
- Weather routing
- WebGL rotating F
- WiktionaryDumps to words
- Wolstenholme numbers
- Word break problem
- Words from neighbour ones
- Worthwhile task shaving
X
Tasks omitted from R
A
B
C
E
F
J
M
S
End of List
Again, feel free to try your hand at any of the tasks listed on this page.