# Reports:Tasks not implemented in Pascal

**Awareness**

If

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

## Contents

## Not implemented[edit]

These are currently not implemented in Pascal. Please implement some if you can. If any tasks are not possible or too complex in Pascal, they should not be on this list. To mark a task as such, add **{{omit from|Pascal}}**, 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, simple
- Abelian sandpile model/Identity
- Accumulator factory
- Active Directory/Connect
- Active Directory/Search for a user
- Active object
- Aliquot sequence classifications
- Almkvist-Giullera formula for pi
- Amb
- Angles (geometric), normalization and conversion
- Animate a pendulum
- Anonymous recursion
- Apply a digital filter (direct form II transposed)
- Approximate equality
- Archimedean spiral
- Arithmetic-geometric mean/Calculate Pi
- Arithmetic/Rational
- Associative array/Creation
- Associative array/Iteration
- Associative array/Merging
- Atomic updates
- Average loop length
- Averages/Mean time of day
- Averages/Mode

### B

- Balanced ternary
- Barnsley fern
- Base64 decode data
- Bin given limits
- Bioinformatics/Sequence mutation
- Biorhythms
- Bitcoin/address validation
- Bitcoin/public point to address
- Bitmap/Bézier curves/Cubic
- Bitmap/Bézier curves/Quadratic
- 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
- Break OO privacy
- Brownian tree
- Bulls and cows/Player

### C

- CRC-32
- CSV to HTML translation
- CUSIP
- Calendar
- Calendar - for "REAL" programmers
- Call a function
- Call an object method
- Canny edge detector
- Canonicalize CIDR
- Cantor set
- Carmichael 3 strong pseudoprimes
- Cartesian product of two or more lists
- Casting out nines
- 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
- Church numerals
- Circles of given radius through two points
- 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 a list of strings
- Compare sorting algorithms' performance
- Compiler/AST interpreter
- Compiler/code generator
- Compiler/lexical analyzer
- Compiler/syntax analyzer
- Compiler/virtual machine interpreter
- Conjugate transpose
- Consecutive primes with ascending or descending differences
- Constrained genericity
- Constrained random points on a circle
- Continued fraction
- Continued fraction/Arithmetic/Construct from rational number
- Convert decimal number to rational
- Convert seconds to compound duration
- Convex hull
- Count the coins
- Cramer's rule
- Create a file on magnetic tape
- Currency
- Currying
- Cut a rectangle
- Cyclotomic polynomial

### D

- DNS query
- De Bruijn sequences
- Deal cards for FreeCell
- Death Star
- Deconvolution/1D
- Deconvolution/2D+
- Deepcopy
- Deming's Funnel
- Department numbers
- Determinant and permanent
- 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 sentence type
- Dice game probabilities
- Dinesman's multiple-dwelling problem
- Display a linear combination
- Display an outline as a nested table
- Distributed programming
- Diversity prediction theorem
- Documentation
- Doubly-linked list/Definition
- Draw a clock
- Draw a pixel
- Draw a rotating cube
- Dutch national flag problem

### E

- EKG sequence convergence
- Eban numbers
- Echo server
- Eertree
- Egyptian division
- Egyptian fractions
- Element-wise operations
- Elementary cellular automaton
- Elementary cellular automaton/Infinite length
- Elliptic Curve Digital Signature Algorithm
- Elliptic curve arithmetic
- Empty directory
- Entropy/Narcissist
- Euler's constant 0.5772...
- Euler's identity
- Events
- Executable library
- Execute SNUSP
- Execute a Markov algorithm
- Exponentiation order
- Exponentiation with infix operators in (or operating on) the base
- Extend your language

### F

- FTP
- Faces from a mesh
- Factorial base numbers indexing permutations of a collection
- Fairshare between two and more
- Faulhaber's formula
- Faulhaber's triangle
- Feigenbaum constant calculation
- Fermat numbers
- Fibonacci word/fractal
- File extension is in extensions list
- File size distribution
- Find Chess960 starting position identifier
- Find common directory path
- 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 a line with a plane
- Find the intersection of two lines
- Find the last Sunday of each month
- First-class functions
- First class environments
- Fivenum
- Flatten a list
- Flipping bits game
- Floyd-Warshall algorithm
- Forest fire
- Fork
- Formal power series
- Fortunate numbers
- Four bit adder
- Four is magic
- Four is the number of letters in the ...
- Fractal tree
- Fractran
- French Republican calendar
- Function frequency
- Function prototype
- Functional coverage tree

### G

- GUI/Maximum window dimensions
- GUI component interaction
- GUI enabling/disabling of controls
- Galton box animation
- Gamma function
- Gauss-Jordan matrix inversion
- Gaussian elimination
- General FizzBuzz
- Generate Chess960 starting position
- Generate random chess position
- Generator/Exponential
- Get system command output
- Go Fish
- Graph colouring
- Grayscale image
- Greyscale bars/Display

### H

- HTTPS/Authenticated
- HTTPS/Client-authenticated
- Handle a signal
- Hash join
- Hello world/Newbie
- Hello world/Web server
- Hickerson series of almost integers
- Hilbert curve
- History variables
- Hofstadter Figure-Figure sequences
- Holidays related to Easter
- Honeycombs
- Hough transform
- Huffman coding
- Hunt the Wumpus

### I

- IBAN
- I before E except after C
- Idiomatically determine all the characters that can be used for symbols
- Idiomatically determine all the lowercase and uppercase letters
- Image convolution
- Imaginary base numbers
- Index finite lists of positive integers
- Integer overflow
- Intersecting number wheels
- Introspection
- Inverted index

### J

### K

- K-d tree
- K-means++ clustering
- Kaprekar numbers
- Kernighans large earthquake problem
- Keyboard input/Flush the keyboard buffer
- Keyboard input/Keypress check
- Keyboard macros
- Knapsack problem/Bounded
- Knapsack problem/Continuous
- 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 number divisible by its digits
- Last Friday of each month
- Last letter-first letter
- Latin Squares in reduced form
- Latin Squares in reduced form/Randomizing using Jacobson and Matthews’ Technique
- Law of cosines - triples
- Left factorials
- Legendre prime counting function
- Leonardo numbers
- Levenshtein distance/Alignment
- List comprehensions
- List rooted trees
- Literals/Floating point
- Longest increasing subsequence
- Loops/Increment loop index within loop body
- Loops/With multiple ranges
- Loops/Wrong ranges
- Lucky and even lucky numbers

### M

- MAC Vendor Lookup
- MD4
- MD5
- MD5/Implementation
- Magic 8-ball
- 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
- Matrix multiplication
- Mayan calendar
- Mayan numerals
- Maze generation
- Maze solving
- McNuggets problem
- Median filter
- Merge and aggregate datasets
- Metallic ratios
- Metaprogramming
- Metered concurrency
- Metronome
- Miller–Rabin primality test
- Mind boggling card trick
- Minesweeper game
- Minimal steps down to 1
- Minkowski question-mark function
- Modified random distribution
- Modular arithmetic
- Monads/List monad
- Monads/Maybe monad
- Monads/Writer monad
- Motzkin numbers
- Mouse position
- Move-to-front algorithm
- Multi-dimensional array
- Multifactorial
- Multiple regression
- Multiplicative order
- Multisplit
- Munching squares
- Musical scale
- Mutex

### N

- Narcissist
- Nautical bell
- Negative base numbers
- Nested templated data
- Next highest int from digits
- Nim game
- Nimber arithmetic
- Non-continuous subsequences
- Non-decimal radices/Output
- Non-transitive dice
- Nonoblock
- Nonogram solver
- Numbers with equal rises and falls
- Numeric error propagation
- Numerical and alphabetical suffixes

### O

### P

- P-Adic numbers, basic
- P-Adic square roots
- P-value correction
- Padovan n-step number sequences
- Padovan sequence
- Palindrome dates
- Pancake numbers
- Parallel brute force
- Parallel calculations
- Parametric polymorphism
- Parse an IP Address
- Parsing/RPN calculator algorithm
- Parsing/RPN to infix conversion
- Parsing/Shunting-yard algorithm
- Partial function application
- Partition an integer x into n primes
- Partition function P
- Pascal's triangle/Puzzle
- Pathological floating point problems
- Peaceful chess queen armies
- Peano curve
- Pell's equation
- Pentagram
- Pentomino tiling
- Percentage difference between images
- Percolation/Bond percolation
- Percolation/Mean cluster density
- Percolation/Site percolation
- Perfect shuffle
- Peripheral drift illusion
- Permutation test
- Permutations/Derangements
- Permutations/Rank of a permutation
- Permutations by swapping
- Phrase reversals
- Pierpont primes
- Pig the dice game/Player
- Pinstripe/Display
- Pinstripe/Printer
- Pisano period
- Plasma effect
- Play recorded sounds
- Playfair cipher
- Plot coordinate pairs
- Poker hand analyser
- Polymorphic copy
- Polynomial long division
- Polynomial regression
- Polyspiral
- Power set
- Pragmatic directives
- Primality by Wilson's theorem
- Primes - allocate descendants to their ancestors
- Probabilistic choice
- Problem of Apollonius
- 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
- Pythagoras tree

### R

- RCRPG
- RIPEMD-160
- RSA code
- Ramanujan's constant
- Ramanujan primes/twins
- Ramer-Douglas-Peucker line simplification
- Random Latin squares
- Random sentence from book
- Range consolidation
- Range expansion
- Ranking methods
- Rare numbers
- Rate counter
- Ray-casting algorithm
- Recaman's sequence
- Record sound
- Reduced row echelon form
- Reflection/Get source
- Reflection/List methods
- Reflection/List properties
- Rendezvous
- Rep-string
- Resistor mesh
- Respond to an unknown method call
- Retrieve and search chat history
- Rock-paper-scissors
- 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

### S

- S-expressions
- SHA-256
- SOAP
- SQL-based authentication
- Safe addition
- Sailors, coconuts and a monkey problem
- Same fringe
- Scope/Function names and labels
- Search a list of records
- Semordnilap
- Send an unknown method call
- Send email
- Sequence: nth number with exactly n divisors
- Sequence: smallest number with exactly n divisors
- Sequence of primorial primes
- Set consolidation
- Set of real numbers
- Set puzzle
- Set right-adjacent bits
- Seven-sided dice from five-sided dice
- Shoelace formula for polygonal area
- Shortest common supersequence
- Show ASCII table
- Sierpinski arrowhead curve
- Sierpinski pentagon
- Sierpinski square curve
- Sierpinski triangle/Graphical
- Simple database
- Simulate input/Keyboard
- Simulate input/Mouse
- Snake
- 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 integer array
- 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/Radix sort
- Sparkline in unicode
- Speech synthesis
- Spelling of ordinal numbers
- Spinning rod animation/Text
- Square-free integers
- Square form factorization
- Stable marriage problem
- Stack traces
- State name puzzle
- Statistics/Basic
- Stem-and-leaf plot
- Stirling numbers of the first kind
- Stirling numbers of the second kind
- Straddling checkerboard
- Strassen's algorithm
- Stream merge
- String comparison
- String interpolation (included)
- String matching
- Strip block comments
- Substitution cipher
- Subtractive generator
- Successive prime differences
- Suffixation of decimal numbers
- Sum and product puzzle
- Sum of elements below main diagonal of matrix
- Summarize and say sequence
- Summarize primes
- Superellipse
- Superpermutation minimisation
- Sutherland-Hodgman polygon clipping
- Sylvester's sequence
- Synchronous concurrency

### T

- Table creation/Postal addresses
- Tarjan
- Teacup rim text
- Terminal control/Cursor movement
- Terminal control/Dimensions
- Terminal control/Hiding the cursor
- Terminal control/Positional read
- Terminal control/Preserve screen
- Terminal control/Unicode output
- Text processing/1
- Text processing/2
- Text processing/Max licenses in use
- Textonyms
- The Name Game
- The sieve of Sundaram
- Thiele's interpolation formula
- Tic-tac-toe
- Time a function
- Tokenize a string with escaping
- Tonelli-Shanks algorithm
- Topswops
- Total circles area
- Trabb Pardo–Knuth algorithm
- Tree datastructures
- Tree from nesting levels
- Tree traversal
- Truncatable primes
- Twin primes
- Two bullet roulette

### U

### V

- Validate International Securities Identification Number
- Vampire number
- Variable-length quantity
- Vector
- 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

### 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 Pascal (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
- ABC words
- ADFGVX cipher
- Addition-chain exponentiation
- Addition chains
- Air mass
- Alternade words
- Append numbers at same position in strings
- Arithmetic coding/As a generalized change of radix
- Aspect oriented programming
- Assertions in design by contract
- Audio alarm
- Audio frequency generator
- Audio overlap loop

### B

### C

- CLI-based maze-game
- Camel case and snake case
- Card shuffles
- Change e letters to i in words
- 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
- Combinations with repetitions/Square digit chain
- Common list elements
- Common sorted list
- 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
- Create an object/Native demonstration
- Create your own text control codes
- Cubic Special Primes
- Cullen and Woodall numbers
- 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
- Diophantine linear system solving
- Discrete Fourier transform
- Distinct Palindromes within decimal numbers
- Distinct power numbers
- Divide a rectangle into a number of unequal triangles
- Dominoes
- Doomsday rule
- Doubly-linked list/Element removal
- Draw pixel 2

### E

### F

- 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 which contain the most consonants
- Find words which contains all the vowels
- Find words whose first and last three letters are equal
- Find words with alternating vowels and consonants
- First 9 Prime Fibonacci Number
- Free polyominoes enumeration
- Frobenius numbers

### G

### I

### L

- 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
- Line circle intersection
- Linux CPU utilization
- Logistic curve fitting in epidemiology
- Longest common prefix
- Longest common suffix
- Longest palindromic substrings
- Longest substrings without repeating characters

### M

- Magic constant
- Make a backup file
- Markov chain text generator
- Mersenne primes
- Minimum multiple of m where digital sum equals m
- Minimum numbers of three lists
- Minimum primes
- Montgomery reduction
- Morpion solitaire
- Most frequent k chars distance
- Multidimensional Newton-Raphson method
- Multiline shebang
- Multiton

### N

- NYSIIS
- Names to numbers
- Native shebang
- Neighbour primes
- Nice primes
- Number triplets game
- 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
- Numeric separator syntax
- Numerical integration/Adaptive Simpson's method

### O

### P

- Palindromic primes
- Palindromic primes in base 16
- Pandigital prime
- Parse EBNF
- Parse command-line arguments
- Particle fountain
- Particle swarm optimization
- Penrose tiling
- Piprimes
- Polynomial derivative
- Polynomial synthetic division
- Powerful numbers
- Price list behind API
- Prime numbers p which sum of prime numbers less or equal to p is prime
- Prime numbers which contain 123
- Prime triplets
- Prime words
- Primes which contain only one odd digit
- Primes whose first and last number is 3
- 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

- Railway circuit
- Ramanujan primes
- Ramsey's theorem
- Range modifications
- Raster bars
- Readline interface
- Recursive descent parser generator
- Remote agent/Agent interface
- Remote agent/Agent logic
- Remote agent/Simulation
- Remove vowels from a string
- Repunit primes
- Resistance calculator
- Resistance network calculator
- Reverse the gender of a string
- 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
- Sattolo cycle
- Segmentation fault protection
- Selective file copy
- Self-hosting compiler
- Separate the house number from the street name
- Shift list elements to left by 3
- Sierpinski curve
- Simple turtle graphics
- Simulated annealing
- Sine wave
- Singly-linked list/Element removal
- Smallest enclosing circle problem
- Smallest number k such that k+2^m is composite for all m less than k
- Smallest square that begins with n
- Snake and Ladder
- Solve a Rubik's Cube
- Solve equations with substitution method
- 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 plus numbers
- Subset sum problem
- Substring primes
- Suffix tree
- 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
- Sunflower fractal

### 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
- Triplet of three numbers
- Tropical algebra overloading
- Type detection

### U

### W

## Requiring Attention[edit]

### Examples[edit]

These tasks have implementations in Pascal, 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 Pascal 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 Pascal 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.