# Reports:Tasks not implemented in Fortran

**Awareness**

If

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

## Contents

## Not implemented[edit]

These are currently not implemented in Fortran. Please implement some if you can. If any tasks are not possible or too complex in Fortran, they should not be on this list. To mark a task as such, add **{{omit from|Fortran}}**, 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/Identity
- Abundant odd numbers
- Active Directory/Connect
- Active Directory/Search for a user
- Active object
- Amb
- Anagrams/Deranged anagrams
- Angles (geometric), normalization and conversion
- Animation
- Apply a digital filter (direct form II transposed)
- Archimedean spiral
- Arithmetic-geometric mean/Calculate Pi
- Arithmetic evaluation
- Assertions
- Associative array/Creation
- Associative array/Iteration
- Associative array/Merging
- Atomic updates
- Average loop length

### B

- Balanced ternary
- Base64 decode data
- Bell numbers
- Bernoulli numbers
- Best shuffle
- Bin given limits
- Binary strings
- Bioinformatics/Sequence mutation
- Bioinformatics/base count
- Bitcoin/address validation
- Bitcoin/public point to address
- Bitmap/PPM conversion through a pipe
- Bitmap/Read an image through a pipe
- Bitwise IO
- Brace expansion
- Brazilian numbers
- Break OO privacy
- Burrows–Wheeler transform

### C

- Calkin-Wilf sequence
- Canny edge detector
- Canonicalize CIDR
- Cantor set
- Cartesian product of two or more lists
- Casting out nines
- Catalan numbers/Pascal's triangle
- Catmull–Clark subdivision surface
- Chaocipher
- 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
- Circular primes
- Cistercian numerals
- Closures/Value capture
- Color of a screen pixel
- Color quantization
- Color wheel
- Colour bars/Display
- Colour pinstripe/Display
- Colour pinstripe/Printer
- Combinations and permutations
- Commatizing numbers
- Compare sorting algorithms' performance
- Compiler/AST interpreter
- Compiler/code generator
- Compiler/lexical analyzer
- Compiler/syntax analyzer
- Compiler/virtual machine interpreter
- Continued fraction/Arithmetic/Construct from rational number
- Convex hull
- Copy stdin to stdout
- Count the coins
- Create an object at a given address
- Cuban primes
- Currency
- Currying
- Cut a rectangle
- Cyclotomic polynomial

### D

- DNS query
- Date manipulation
- De Bruijn sequences
- Death Star
- Deconvolution/2D+
- Deepcopy
- Deming's Funnel
- Determine if a string has all the same characters
- Determine if a string has all unique characters
- Determine if a string is collapsible
- Determine if a string is squeezable
- Determine if only one instance is running
- Determine if two triangles overlap
- Dice game probabilities
- Dijkstra's algorithm
- Dinesman's multiple-dwelling problem
- Dining philosophers
- Display a linear combination
- Display an outline as a nested table
- Distributed programming
- Diversity prediction theorem
- Dragon curve
- Draw a cuboid
- Draw a pixel
- Draw a rotating cube
- Draw a sphere

### E

- EKG sequence convergence
- Eban numbers
- Echo server
- Eertree
- Egyptian division
- Egyptian fractions
- 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
- Events
- Exceptions
- Exceptions/Catch an exception thrown in a nested call
- Executable library
- Execute SNUSP
- Execute a Markov algorithm
- Exponentiation with infix operators in (or operating on) the base

### F

- FASTA format
- FTP
- Faces from a mesh
- Factorial base numbers indexing permutations of a collection
- Factorions
- Fairshare between two and more
- Farey sequence
- Faulhaber's formula
- Faulhaber's triangle
- Fermat numbers
- Fibonacci word
- Fibonacci word/fractal
- File size distribution
- Find common directory path
- Find duplicate files
- Find palindromic numbers in both binary and ternary bases
- Find the intersection of a line with a plane
- First-class functions
- First class environments
- First perfect square in base n with n unique digits
- First power of 2 that has leading decimal digits of 12
- Fivenum
- Fixed length records
- Floyd-Warshall algorithm
- Fork
- Formal power series
- Four is magic
- Four is the number of letters in the ...
- Fractal tree
- Fraction reduction
- French Republican calendar
- Function frequency
- Function prototype
- Functional coverage tree
- Fusc sequence

### G

### H

### I

- 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
- Index finite lists of positive integers
- Inheritance/Multiple
- Intersecting number wheels
- Introspection
- Inverted index
- Isqrt (integer square root) of X
- Iterated digits squaring

### K

### L

- Lah numbers
- Largest number divisible by its digits
- Last letter-first letter
- Latin Squares in reduced form
- Law of cosines - triples
- Levenshtein distance
- Levenshtein distance/Alignment
- List rooted trees
- Long literals, with continuations
- Long primes
- Longest common substring
- Longest increasing subsequence
- Longest string challenge
- Loops/With multiple ranges
- Loops/Wrong ranges
- Lucky and even lucky numbers

### M

- MAC Vendor Lookup
- MD4
- MD5/Implementation
- Machine code
- Magic squares of doubly even order
- Magic squares of singly even order
- Main step of GOST 28147-89
- Make directory path
- Mastermind
- Matrix digital rain
- Mayan numerals
- Maze generation
- Maze solving
- McNuggets problem
- Median filter
- Merge and aggregate datasets
- Metallic ratios
- Metaprogramming
- Metered concurrency
- Metronome
- Mian-Chowla sequence
- Mind boggling card trick
- Minesweeper game
- Minimal steps down to 1
- Minkowski question-mark function
- Modified random distribution
- Modular arithmetic
- Modular exponentiation
- Modular inverse
- Monads/List monad
- Monads/Maybe monad
- Monads/Writer monad
- Morse code
- Mouse position
- Move-to-front algorithm
- Multiplicative order
- Multisplit
- Munching squares
- Musical scale
- Mutex

### N

### O

### 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
- Parametrized SQL statement
- Parse an IP Address
- Parsing/RPN to infix conversion
- Partial function application
- Partition an integer x into n primes
- Partition function P
- Pascal's triangle/Puzzle
- Password generator
- Pattern matching
- Peaceful chess queen armies
- Peano curve
- Pell's equation
- Penney's game
- Pentagram
- Percolation/Bond percolation
- Percolation/Mean cluster density
- Perfect shuffle
- Perfect totient numbers
- Perlin noise
- Permutation test
- Permutations/Derangements
- Permutations/Rank of a permutation
- Permutations by swapping
- Pierpont primes
- Pig the dice game
- Pig the dice game/Player
- Pinstripe/Display
- Pinstripe/Printer
- Plasma effect
- Play recorded sounds
- Playfair cipher
- Plot coordinate pairs
- Poker hand analyser
- Polyspiral
- Power set
- Pragmatic directives
- Primality by Wilson's theorem
- Primes - allocate descendants to their ancestors
- Pseudo-random numbers/Combined recursive generator MRG32k3a
- Pseudo-random numbers/PCG32
- Pseudo-random numbers/Xorshift star
- Pythagoras tree
- Pythagorean quadruples

### R

- RCRPG
- RIPEMD-160
- RPG attributes generator
- RSA code
- Ramanujan's constant
- Ramer-Douglas-Peucker line simplification
- Random Latin squares
- Random sentence from book
- Range consolidation
- Ranking methods
- Rare numbers
- Read a file character by character/UTF8
- Recaman's sequence
- Record sound
- Reflection/Get source
- Reflection/List methods
- Regular expressions
- Rendezvous
- Rep-string
- Repeat
- Resistor mesh
- Respond to an unknown method call
- Retrieve and search chat history
- 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
- Runtime evaluation/In an environment

### S

- S-expressions
- SHA-256 Merkle tree
- SOAP
- SQL-based authentication
- Safe addition
- Safe primes and unsafe primes
- Sailors, coconuts and a monkey problem
- Same fringe
- Scope/Function names and labels
- Scope modifiers
- Self-describing numbers
- Self numbers
- Semiprime
- Send an unknown method call
- 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
- Set
- Set consolidation
- Set of real numbers
- Set puzzle
- Sexy primes
- Shortest common supersequence
- Sierpinski pentagon
- Sierpinski triangle/Graphical
- Simple database
- Simple windowed application
- Simulate input/Keyboard
- Simulate input/Mouse
- Singleton
- Smarandache prime-digital sequence
- 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 a list of object identifiers
- Sort an outline at every level
- Sort numbers lexicographically
- Sorting algorithms/Cocktail sort with shifting bounds
- Sorting algorithms/Patience sort
- Sorting algorithms/Permutation sort
- Sorting algorithms/Strand sort
- Soundex
- Sparkline in unicode
- Speech synthesis
- Spelling of ordinal numbers
- Spinning rod animation/Text
- Square-free integers
- Square Form Factorization
- Square but not cube
- Stable marriage problem
- Start from a main routine
- State name puzzle
- Stirling numbers of the first kind
- Stirling numbers of the second kind
- Straddling checkerboard
- Strong and weak primes
- Successive prime differences
- Suffixation of decimal numbers
- Sum and product puzzle
- Summarize and say sequence
- Sunflower fractal
- Super-d numbers
- Superellipse
- Superpermutation minimisation
- Synchronous concurrency

### T

- Table creation/Postal addresses
- Take notes on the command line
- Tarjan
- Tau function
- Tau number
- Taxicab numbers
- Teacup rim text
- Terminal control/Cursor movement
- 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
- Textonyms
- The ISAAC Cipher
- The Name Game
- Thiele's interpolation formula
- Tonelli-Shanks algorithm
- Topic variable
- Total circles area
- Totient function
- Tree datastructures
- Tree from nesting levels
- Truth table
- Twelve statements

### U

### V

### W

### Draft tasks without implementation[edit]

These tasks are drafts, meaning they largely need more work to turn them into full tasks. Perhaps you can help by trying to implement them in Fortran (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
- Card shuffles
- Change e letters to i in words
- Changeable words
- Chebyshev coefficients
- Checksumcolor
- Chemical calculator
- Chess player
- Cipolla's algorithm
- Code segment unload
- Combinations with repetitions/Square digit chain
- Common list elements
- Common sorted list
- Compiler/Verifying syntax
- Consecutive Primes With Ascending Or Descending Differences
- Continued fraction/Arithmetic/G(matrix ng, continued fraction n)
- Continued fraction/Arithmetic/G(matrix ng, continued fraction n1, continued fraction n2)
- Count the coins/0-1
- Cousin primes
- Create an object/Native demonstration
- Cubic Special Primes
- Curve that touches three points
- Cycle detection

### D

### F

- Fibonacci heap
- Fibonacci matrix-exponentiation
- Find URI in text
- Find first missing positive
- Find if a point is within a triangle
- Find prime n for that reversed n is also prime
- Find prime numbers of the form n*n*n+2
- Find words which contains all the vowels
- Find words which contains more than 3 e vowels
- Find words which contains most consonants
- Find words which first and last three letters are equals
- Find words with alternating vowels and consonants
- Finite state machine
- Free polyominoes enumeration
- Frobenius numbers

### G

### I

### L

### M

### N

- NYSIIS
- Names to numbers
- Native shebang
- Neighbour primes
- Next special primes
- Nice primes
- Numbers divisible by their individual digits, but not by the product of their digits.
- Numbers which binary and ternary digit sum are prime
- Numbers with prime digits whose sum is 13
- Numeric separator syntax
- Numerical integration/Adaptive Simpson's method

### O

### P

- Palindromic primes
- Parse EBNF
- Parse command-line arguments
- Particle swarm optimization
- Penrose tiling
- Pentomino tiling
- Perceptron
- Permutations with repetitions
- Permutations with some identical elements
- Piprimes
- Pisano period
- Polynomial synthetic division
- Powerful numbers
- Practical numbers
- Price list behind API
- Prime triplets
- Prime words
- Primes which 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
- Pseudo-random numbers/Splitmix64
- Pseudorandom number generator image

### R

- Railway circuit
- 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
- Robots
- Rosetta Code/List authors of task descriptions
- Rosetta Code/Run examples
- Rosetta Code/Tasks without examples
- Run as a daemon or service

### S

- Safe mode
- Sattolo cycle
- 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 arrowhead curve
- Sierpinski curve
- Sierpinski square curve
- Simulated annealing
- Sine wave
- Smallest enclosing circle problem
- Smallest numbers
- Smallest power of 6 whose decimal expansion contains n
- Smallest square that begins with n
- Snake
- Snake and Ladder
- Solve a Rubik's Cube
- Solve triangle solitare puzzle
- Solving coin problems
- Sorting algorithms/Cycle sort
- Sorting algorithms/Tree sort on a linked list
- Special Divisors
- Special factorials
- Spoof game
- Square root by hand
- Starting a web browser
- Strange numbers
- Strange plus numbers
- Strange unique prime triplets
- Strassen's algorithm
- Subset sum problem
- Substring primes
- Suffix tree
- Sum data type
- Sum of divisors
- Sum of the digits of n is substring of n
- Summarize primes

### 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
- Twin primes
- Two bullet roulette
- Type detection

### U

### W

## Requiring Attention[edit]

### Examples[edit]

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

### G

## Not Considered[edit]

These tasks are not generally counted toward "unimplemented", as somebody, somewhere, decided that Fortran 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.