# Reports:Tasks not implemented in Ruby

**Awareness**

If

**Ruby**is a language you like, or are interested in, please inform your fellow members of the Ruby community; this page can't be emptied without your and their participation.

## Contents

## Not implemented[edit]

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

### A

### C

- Canny edge detector
- Catmull–Clark subdivision surface
- Chaos game
- Check Machin-like formulas
- Chernick's Carmichael numbers
- Color quantization
- Colorful numbers
- Colour pinstripe/Display
- Colour pinstripe/Printer
- Commatizing numbers
- 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
- Copy stdin to stdout
- Cullen and Woodall numbers
- Curzon numbers
- Cyclotomic polynomial

### D

### E

### F

### G

### K

### L

### M

- MD5/Implementation
- Machine code
- Magic constant
- Main step of GOST 28147-89
- Mastermind
- Matrix chain multiplication
- Matrix digital rain
- Mayan calendar
- Merge and aggregate datasets
- Minimal steps down to 1
- Minimum multiple of m where digital sum equals m
- Minkowski question-mark function
- Modified random distribution
- Multi-base primes
- Multi-dimensional array
- Musical scale

### N

### P

- P-Adic numbers, basic
- P-Adic square roots
- Padovan n-step number sequences
- Parallel brute force
- Parallel calculations
- Particle fountain
- Partition function P
- Pell numbers
- Pentagram
- Pentomino tiling
- Percolation/Bond percolation
- Percolation/Mean cluster density
- Percolation/Mean run density
- Percolation/Site percolation
- Periodic table
- Peripheral drift illusion
- Perlin noise
- Pinstripe/Display
- Pinstripe/Printer
- Pisano period
- Polyspiral
- Pragmatic directives
- Prime triangle
- Primes - allocate descendants to their ancestors

### R

### S

- SHA-256 Merkle tree
- Same fringe
- Search in paragraph's text
- Selectively replace multiple instances of a character within a string
- Self numbers
- Set right-adjacent bits
- Sierpinski square curve
- Simple turtle graphics
- Simulate input/Keyboard
- Simulate input/Mouse
- Smallest number k such that k+2^m is composite for all m less than k
- Snake
- Sort an outline at every level
- Sorting algorithms/Cocktail sort with shifting bounds
- Spelling of ordinal numbers
- Square form factorization
- Strassen's algorithm
- Suffixation of decimal numbers
- Superellipse

### T

### 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 Ruby (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

### B

### C

- CLI-based maze-game
- Camel case and snake case
- Checksumcolor
- Chess player
- Cipolla's algorithm
- Code Golf: Code Golf
- Code segment unload
- Collect and sort square numbers in ascending order from three lists
- Compiler/Preprocessor
- Compiler/Simple file inclusion pre processor
- Compiler/Verifying syntax
- Conjugate a Latin verb
- Continued fraction/Arithmetic/G(matrix ng, continued fraction n1, continued fraction n2)
- Count the coins/0-1
- Create an executable for a program in an interpreted language
- Create your own text control codes
- Cross compilation
- Cubic special primes
- Curve that touches three points
- Cycles of a permutation

### D

- Data Encryption Standard
- Dating agency
- 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
- Fibonacci heap
- Fibonacci matrix-exponentiation
- Find minimum number of coins that make a given value
- Find prime n such that reversed n is also prime
- Find prime numbers of the form n*n*n+2
- Find square difference
- Find squares n where n+1 is prime
- Find words which contain the most consonants
- Finite state machine
- First 9 prime Fibonacci number
- Four sides of square
- Frobenius numbers

### G

### I

### L

- Largest difference between adjacent primes
- Largest palindrome product
- Largest prime factor
- Largest product in a grid
- Last list item
- Launch rocket with countdown and acceleration in stdout
- Linux CPU utilization
- Long stairs
- Longest common suffix
- Longest palindromic substrings
- Longest substrings without repeating characters

### M

### N

- N-body problem
- N-queens minimum and knights and bishops
- NYSIIS
- Neighbour primes
- Next special primes
- Nice primes
- Nimber arithmetic
- Number triplets game
- Numbers divisible by their individual digits, but not by the product of their digits.
- Numbers in base-16 representation that cannot be written with decimal digits
- Numbers in base 10 that are palindromic in bases 2, 4, and 16
- Numbers which binary and ternary digit sum are prime
- Numbers whose count of divisors is prime
- Numbers with same digit set in base 10 and base 16
- Numerical integration/Adaptive Simpson's method

### O

### P

- Palindromic primes
- Palindromic primes in base 16
- Pan base non-primes
- Particle swarm optimization
- Penrose tiling
- Perceptron
- Permutations with some identical elements
- Permuted multiples
- Piprimes
- Polynomial derivative
- Polynomial synthetic division
- Positive decimal integers with the digit 1 occurring exactly twice
- Powerful numbers
- Practical numbers
- Price list behind API
- Prime numbers p for which the sum of primes less than or equal to p is prime
- Prime triplets
- Primes which contain only one odd digit
- Primes whose first and last number is 3
- Primes with digits in nondecreasing order
- Primorial primes
- Print debugging statement
- Print itself
- Process SMIL directives in XML data
- Pseudorandom number generator image

### R

- Railway circuit
- Ramanujan primes
- Range modifications
- Raster bars
- 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
- 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
- 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
- Solve a Rubik's cube
- Solve equations with substitution method
- Solve hanging lantern problem
- Solving coin problems
- Sort primes from list to a list
- Sort the letters of string in alphabetical order
- Sorting algorithms/Tree sort on a linked list
- Special divisors
- Special factorials
- Special neighbor primes
- Special pythagorean triplet
- Spoof game
- Square root by hand
- Starting a web browser
- Steady squares
- Strange unique prime triplets
- Substring primes
- Suffix tree
- Sum data type
- Sum of first n cubes
- 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
- Sunflower fractal

### T

- 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
- Type detection

### U

### W

## Requiring Attention[edit]

### Examples[edit]

These tasks have implementations in Ruby, 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.

### C

### I

### P

### Y

### Other pages[edit]

These are other pages related to Ruby 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 Ruby 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.