Reports:Tasks not implemented in COBOL
From Rosetta Code
Awareness
If COBOL is a language you like, or are interested in, please inform your fellow members of the COBOL community; this page can't be emptied without your and their participation.
If COBOL is a language you like, or are interested in, please inform your fellow members of the COBOL community; this page can't be emptied without your and their participation.
Contents
Not implemented[edit]
These are currently not implemented in COBOL. Please implement some if you can. If any tasks are not possible or too complex in COBOL, they should not be on this list. To mark a task as such, add {{omit from|COBOL}}, preserving the capitalization of the language, to that task. It will appear below under the "Not Considered" section.
A
- ABC Problem
- 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
- Abundant odd numbers
- Accumulator factory
- Active Directory/Connect
- Active Directory/Search for a user
- Active object
- Add a variable to a class instance at runtime
- Aliquot sequence classifications
- Almost prime
- Amb
- Amicable pairs
- Anagrams/Deranged anagrams
- Angle difference between two bearings
- Angles (geometric), normalization and conversion
- Animate a pendulum
- Animation
- Anonymous recursion
- Anti-primes
- Apply a digital filter (direct form II transposed)
- Approximate Equality
- Archimedean spiral
- Arena storage pool
- Arithmetic-geometric mean/Calculate Pi
- Arithmetic/Rational
- Arithmetic evaluation
- Assertions
- Associative array/Creation
- Associative array/Iteration
- Associative array/Merging
- Atomic updates
- Attractive numbers
- Average loop length
- Averages/Mean angle
- Averages/Mean time of day
- Averages/Mode
- Averages/Pythagorean means
- Averages/Simple moving average
B
- Balanced ternary
- Barnsley fern
- Base64 decode data
- Bell numbers
- Benford's law
- Bernoulli numbers
- Best shuffle
- Binary strings
- Bioinformatics/Sequence mutation
- Bioinformatics/base count
- 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
- Brace expansion
- Brazilian numbers
- Break OO privacy
- Brownian tree
- Bulls and cows
- Bulls and cows/Player
- Burrows–Wheeler transform
C
- CSV data manipulation
- CSV to HTML translation
- CUSIP
- Canny edge detector
- Canonicalize CIDR
- Cantor set
- 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
- Checkpoint synchronization
- Chernick's Carmichael numbers
- Cheryl's Birthday
- Chinese remainder theorem
- Chinese zodiac
- Cholesky decomposition
- Chowla numbers
- Church Numerals
- Circles of given radius through two points
- Circular primes
- Closest-pair problem
- Closures/Value capture
- Color of a screen pixel
- Color quantization
- Color wheel
- Colour pinstripe/Display
- Colour pinstripe/Printer
- Combinations
- Combinations and permutations
- Combinations with repetitions
- Commatizing numbers
- Compare sorting algorithms' performance
- Compile-time calculation
- Concurrent computing
- Conjugate transpose
- Constrained genericity
- Continued fraction/Arithmetic/Construct from rational number
- Convert decimal number to rational
- Convex hull
- Copy stdin to stdout
- Count in factors
- Cramer's rule
- Create a two-dimensional array at runtime
- Create an HTML table
- 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
- Delegates
- 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 collapsible
- Determine if a string is squeezable
- Determine if only one instance is running
- Determine if two triangles overlap
- Dice game probabilities
- Digital root
- Digital root/Multiplicative digital root
- Dijkstra's algorithm
- Dinesman's multiple-dwelling problem
- Dining philosophers
- Discordian date
- Display a linear combination
- Display an outline as a nested table
- Distributed programming
- Dot product
- 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
- Dutch national flag problem
- Dynamic variable names
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 arithmetic
- Emirp primes
- Empty directory
- Entropy
- Entropy/Narcissist
- Enumerations
- Equilibrium index
- Euler's identity
- Evaluate binomial coefficients
- Events
- Exceptions
- Exceptions/Catch an exception thrown in a nested call
- Executable library
- Execute a Markov algorithm
- Exponentiation operator
- Exponentiation order
- Extensible prime generator
- Extreme floating point values
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 modification time
- File size distribution
- Filter
- Find common directory path
- Find duplicate files
- 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
- 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
- Fivenum
- Flatten a list
- Flipping bits game
- Floyd's triangle
- Floyd-Warshall algorithm
- Formal power series
- Forward difference
- Four is magic
- Four is the number of letters in the ...
- Fractal tree
- Fraction reduction
- Fractran
- Function composition
- Function frequency
- Functional coverage tree
- Fusc sequence
G
- GUI/Maximum window dimensions
- GUI component interaction
- GUI enabling/disabling of controls
- 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
- Generic swap
- 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/With feedback (player)
H
- HTTPS
- HTTPS/Authenticated
- HTTPS/Client-authenticated
- Hamming numbers
- Happy numbers
- Hash from two arrays
- Hash join
- Haversine formula
- Hello world/Web server
- Here document
- Heronian triangles
- Higher-order functions
- Hilbert curve
- History variables
- Hofstadter-Conway $10,000 sequence
- Hofstadter Figure-Figure sequences
- Hofstadter Q sequence
- Honeycombs
- Horner's rule for polynomial evaluation
- Host introspection
- Hough transform
- Huffman coding
- Humble numbers
- Hunt The Wumpus
I
- ISBN13 check digit
- I before E except after C
- Identity matrix
- Idiomatically determine all the characters that can be used for symbols
- Image convolution
- Image noise
- Imaginary base numbers
- Increasing gaps between consecutive Niven numbers
- Index finite lists of positive integers
- Infinity
- Interactive programming
- Intersecting Number Wheels
- Introspection
- Inverted index
- Inverted syntax
- Isqrt (integer square root) of X
- Iterated digits squaring
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/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
- Largest int from concatenated ints
- Largest number divisible by its digits
- Last letter-first letter
- Latin Squares in reduced form
- Law of cosines - triples
- Left factorials
- Leonardo numbers
- Letter frequency
- Levenshtein distance/Alignment
- Linear congruential generator
- List comprehensions
- List rooted trees
- Literals/Floating point
- Long literals, with continuations
- Long primes
- Long year?
- Longest Common Substring
- Longest common subsequence
- Longest increasing subsequence
- Longest string challenge
- Look-and-say sequence
- Loops/Increment loop index within loop body
- Loops/Wrong ranges
- Loops/with multiple ranges
- Lucas-Lehmer test
- Lucky and even lucky numbers
- Ludic numbers
- Lychrel numbers
M
- MAC Vendor Lookup
- MD4
- MD5
- MD5/Implementation
- Mad Libs
- Magic 8-Ball
- Magic squares of doubly even order
- Magic squares of odd order
- Magic squares of singly even order
- Main step of GOST 28147-89
- Make directory path
- Man or boy test
- Mastermind
- Matrix-exponentiation operator
- Matrix Digital Rain
- Matrix chain multiplication
- Matrix multiplication
- Matrix transposition
- Maximum triangle path sum
- Mayan numerals
- Maze generation
- Maze solving
- McNuggets Problem
- Median filter
- Memory layout of a data structure
- Mertens function
- Metallic ratios
- Metaprogramming
- Metered concurrency
- Metronome
- Mian-Chowla sequence
- Miller–Rabin primality test
- Mind boggling card trick
- Minesweeper game
- Minimal steps down to 1
- Modular arithmetic
- Modular exponentiation
- Modular inverse
- Monads/List monad
- Monads/Maybe monad
- Monads/Writer monad
- Monte Carlo methods
- Morse code
- Mouse position
- Move-to-front algorithm
- Multi-dimensional array
- Multifactorial
- Multiple distinct objects
- Multiple regression
- Multiplicative order
- Multisplit
- Munchausen numbers
- Munching squares
- Mutex
- Mutual recursion
N
- N-queens problem
- N-smooth numbers
- Naming conventions
- Narcissist
- Natural sorting
- Nautical bell
- Negative base numbers
- Nested function
- Nested templated data
- Next highest int from digits
- Nim Game
- Non-continuous subsequences
- Non-decimal radices/Convert
- Non-decimal radices/Input
- Non-decimal radices/Output
- Nonoblock
- Nonogram solver
- Number names
- Number reversal game
- Numeric error propagation
- Numerical and alphabetical suffixes
- Numerical integration
- Numerical integration/Gauss-Legendre Quadrature
O
P
- P-value correction
- Palindrome dates
- Palindromic gapful numbers
- Paraffins
- Parallel Brute Force
- Parallel calculations
- Parametric polymorphism
- Parametrized SQL statement
- Parse an IP Address
- Parsing/RPN to infix conversion
- Parsing/Shunting-yard algorithm
- Partial function application
- Partition an integer X into N primes
- 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
- Perlin noise
- Permutation test
- Permutations
- 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
- Plasma effect
- Play recorded sounds
- Playfair cipher
- Plot coordinate pairs
- Poker hand analyser
- Polymorphic copy
- Polymorphism
- Polynomial long division
- Polynomial regression
- Polyspiral
- Population count
- Power set
- Pragmatic directives
- Price fraction
- Primality by Wilson's theorem
- Prime conspiracy
- Prime decomposition
- Primes - allocate descendants to their ancestors
- Primorial numbers
- Priority queue
- Probabilistic choice
- Problem of Apollonius
- Proper divisors
- Pseudo-random numbers/Combined recursive generator MRG32k3a
- Pseudo-random numbers/PCG32
- Pseudo-random numbers/Xorshift star
- Pythagoras tree
- Pythagorean quadruples
- Pythagorean triples
R
- RCRPG
- RIPEMD-160
- RPG Attributes Generator
- RSA code
- Ramanujan's constant
- Ramer-Douglas-Peucker line simplification
- Random number generator (device)
- Random number generator (included)
- Random numbers
- Range consolidation
- Ranking methods
- Rare numbers
- Rate counter
- Ray-casting algorithm
- Read a file character by character/UTF8
- Read a specific line from a file
- Read entire file
- Recaman's sequence
- Record sound
- Reduced row echelon form
- Reflection/Get source
- Reflection/List methods
- Reflection/List properties
- Regular expressions
- Remove duplicate elements
- Remove lines from a file
- Rename a file
- Rendezvous
- Rep-string
- Repeat
- Resistor mesh
- Respond to an unknown method call
- Retrieve and search chat history
- Rock-paper-scissors
- 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 popularity
- Runge-Kutta method
- Runtime evaluation
- Runtime evaluation/In an environment
S
- S-Expressions
- SHA-1
- SHA-256
- SOAP
- SQL-based authentication
- Safe addition
- Safe primes and unsafe primes
- Sailors, coconuts and a monkey problem
- Same Fringe
- Scope/Function names and labels
- Search a list of records
- Secure temporary file
- Self-describing numbers
- Self-referential sequence
- Semiprime
- Semordnilap
- Send an unknown method call
- 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 non-squares
- Sequence of primes by trial division
- Sequence of primorial primes
- Set
- Set consolidation
- Set of real numbers
- Set puzzle
- Seven-sided dice from five-sided dice
- Sexy primes
- Shoelace formula for polygonal area
- Short-circuit evaluation
- Shortest common supersequence
- Show Ascii table
- Sierpinski carpet
- Sierpinski pentagon
- Sierpinski triangle/Graphical
- Simple windowed application
- Simulate input/Keyboard
- Simulate input/Mouse
- Singleton
- Singly-linked list/Element definition
- Singly-linked list/Element insertion
- Singly-linked list/Traversal
- Smarandache prime-digital sequence
- Smith numbers
- 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 array of composite structures
- Sort disjoint sublist
- Sort using a custom comparator
- Sorting Algorithms/Circle Sort
- Sorting algorithms/Cocktail sort with shifting bounds
- Sorting algorithms/Counting sort
- Sorting algorithms/Pancake sort
- Sorting algorithms/Patience sort
- Sorting algorithms/Permutation sort
- Sorting algorithms/Radix sort
- Sorting algorithms/Sleep sort
- Sorting algorithms/Strand sort
- Sparkline in unicode
- Special characters
- Special variables
- Speech synthesis
- Spelling of ordinal numbers
- Spinning rod animation/Text
- Spiral matrix
- Square-free integers
- Square but not cube
- Stable marriage problem
- Stack traces
- Stair-climbing puzzle
- 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
- Stream Merge
- String matching
- Strip block comments
- Strip control codes and extended characters from a string
- Strong and weak primes
- Substitution Cipher
- Subtractive generator
- Successive prime differences
- Sudoku
- Suffixation of decimal numbers
- Sum and Product Puzzle
- Sum digits of an integer
- Sum of squares
- Sum to 100
- Sunflower fractal
- Super-d numbers
- Superellipse
- Superpermutation minimisation
- Sutherland-Hodgman polygon clipping
- Symmetric difference
- Synchronous concurrency
T
- Table creation/Postal addresses
- Tarjan
- Taxicab numbers
- Teacup rim text
- Terminal control/Cursor movement
- Terminal control/Hiding the cursor
- Terminal control/Positional read
- Terminal control/Preserve screen
- Terminal control/Unicode output
- Ternary logic
- Test a function
- Textonyms
- The ISAAC Cipher
- The Name Game
- Thiele's interpolation formula
- Thue-Morse
- Tic-tac-toe
- Time a function
- Tonelli-Shanks algorithm
- Top rank per group
- Topic variable
- Topological sort
- Topswops
- Total circles area
- Totient function
- Trabb Pardo–Knuth algorithm
- Tree datastructures
- Tree traversal
- Truncatable primes
- Truncate a file
- Truth table
- Twelve statements
U
V
- Vampire number
- Van Eck sequence
- Van der Corput sequence
- Variable-length quantity
- Variable size/Set
- Vector
- Vector products
- Verify distribution uniformity/Chi-squared test
- Verify distribution uniformity/Naive
- Video display modes
- Vigenère cipher
- 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 COBOL (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
- Chebyshev coefficients
- Checksumcolor
- Chemical Calculator
- Chess player
- Cipolla's algorithm
- Combinations with repetitions/Square Digit Chain
- Compiler/Verifying Syntax
- Continued fraction/Arithmetic/G(matrix NG, Contined Fraction N)
- Continued fraction/Arithmetic/G(matrix NG, Contined Fraction N1, Contined Fraction N2)
- Create DWM statusbar
- Create an object/Native demonstration
- Curve that touches three points
- Cycle detection
D
E
F
G
H
I
L
- Latin Squares in reduced form/Randomizing using Jacobson and Matthews’ Technique
- 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
- Longest common prefix
- Longest common suffix
- Longest palindromic substrings
M
- Magnanimous numbers
- Make a backup file
- Markov chain text generator
- Mayan calendar
- Mersenne primes
- Minimum positive multiple in base 10 using only 0 and 1
- Modulinos
- Montgomery reduction
- Morpion solitaire
- Most frequent k chars distance
- Multidimensional Newton-Raphson method
- Multiline shebang
- Musical scale
- Möbius function
N
P
- Parse EBNF
- Parse command-line arguments
- Particle Swarm Optimization
- Penrose tiling
- Pentomino tiling
- Perceptron
- Permutations with repetitions
- Permutations with some identical elements
- Pisano period
- Polynomial synthetic division
- Powerful numbers
- Print itself
- Process SMIL directives in XML data
- Proof
- Pseudo-random numbers/Splitmix64
- Pseudorandom Number Generator Image
R
- Railway circuit
- Ramsey's theorem
- Random Latin Squares
- Raster bars
- Readline interface
- Recursive descent parser generator
- 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
- Robots
- Rosetta Code/List authors of task descriptions
- Rosetta Code/Rank languages by number of users
- 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
- Sierpinski arrowhead curve
- Sierpinski curve
- Sierpinski square curve
- Simulated annealing
- Sine wave
- Singly-linked list/Element removal
- Snake
- Snake And Ladder
- Solve a Rubik's Cube
- Solve triangle solitare puzzle
- Solving coin problems
- Sort an outline at every level
- Sorting algorithms/Cycle sort
- Sorting algorithms/Tree sort on a linked list
- Spoof game
- Starting a web browser
- Strassen's algorithm
- Subset sum problem
- Suffix tree
- Sum data type
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 between
- Text to HTML
- Three word location
- Time-based One-time Password Algorithm
- Topological sort/Extracted top item
- Transportation problem
- Twin Prime Conjecture
- Two Sum
- Type detection
U
W
Requiring Attention[edit]
Examples[edit]
These tasks have implementations in COBOL, 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 COBOL 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 COBOL 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.
