# Reports:Tasks not implemented in Delphi

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## Contents

## Not implemented[edit]

These are currently not implemented in Delphi. Please implement some if you can. If any tasks are not possible or too complex in Delphi, they should not be on this list. To mark a task as such, add **{{omit from|Delphi}}**, 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
- Abelian sandpile model/Identity
- Achilles numbers
- Active Directory/Connect
- Active Directory/Search for a user
- Algebraic data types
- Aliquot sequence classifications
- Almkvist-Giullera formula for pi
- Amb
- Append a record to the end of a text file
- Apply a digital filter (direct form II transposed)
- Archimedean spiral
- Ascending primes
- Atomic updates

### B

- Balanced ternary
- Bin given limits
- Bioinformatics/Sequence mutation
- Bitmap/Bézier curves/Cubic
- Bitmap/Bézier curves/Quadratic
- Bitmap/Histogram
- Bitmap/Midpoint circle algorithm
- Bitmap/PPM conversion through a pipe
- Bitmap/Read an image through a pipe
- Brace expansion
- Break OO privacy
- Brilliant numbers
- Bulls and cows/Player
- Burrows–Wheeler transform

### C

- CUSIP
- Calendar - for "REAL" programmers
- Calkin-Wilf sequence
- Call an object method
- Canny edge detector
- Canonicalize CIDR
- Carmichael 3 strong pseudoprimes
- Casting out nines
- Catmull–Clark subdivision surface
- 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
- Church numerals
- Circular primes
- Cistercian numerals
- Color quantization
- Colorful numbers
- Colour pinstripe/Display
- Colour pinstripe/Printer
- Combinations and permutations
- Combinations with repetitions
- Compare length of two strings
- Compare sorting algorithms' performance
- 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
- Conjugate transpose
- Consecutive primes with ascending or descending differences
- Constrained genericity
- Continued fraction
- Continued fraction/Arithmetic/Construct from rational number
- Convert seconds to compound duration
- Cramer's rule
- Cullen and Woodall numbers
- Curzon numbers
- Cyclops numbers
- Cyclotomic polynomial

### D

- De Bruijn sequences
- Deceptive numbers
- Deconvolution/1D
- Deconvolution/2D+
- Deming's funnel
- Descending primes
- Determine sentence type
- Dice game probabilities
- Digital root/Multiplicative digital root
- Dinesman's multiple-dwelling problem
- Disarium numbers
- Display a linear combination
- Display an outline as a nested table
- Distributed programming
- Diversity prediction theorem
- Dominoes
- Duffinian numbers
- Dutch national flag problem

### E

- EKG sequence convergence
- Earliest difference between prime gaps
- Eban numbers
- Eertree
- Egyptian fractions
- Element-wise operations
- Elementary cellular automaton
- Elementary cellular automaton/Infinite length
- Elementary cellular automaton/Random number generator
- Elliptic Curve Digital Signature Algorithm
- Elliptic curve arithmetic
- Entropy/Narcissist
- Equal prime and composite sums
- Erdös-Selfridge categorization of primes
- Esthetic numbers
- Euler's constant 0.5772...
- Executable library
- Execute Computer/Zero
- Execute SNUSP
- Execute a Markov algorithm
- Exponentiation order
- Exponentiation with infix operators in (or operating on) the base

### 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
- 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 a line with a plane
- Find the intersection of two lines
- First-class functions/Use numbers analogously
- First class environments
- First perfect square in base n with n unique digits
- Flatten a list
- Flipping bits game
- Flow-control structures
- Floyd's triangle
- Floyd-Warshall algorithm
- Forest fire
- Formal power series
- Fortunate numbers
- Four is the number of letters in the ...
- Fractal tree
- French Republican calendar
- Function frequency
- Functional coverage tree

### G

### H

- HTTPS/Client-authenticated
- Halt and catch fire
- Handle a signal
- Harmonic series
- Hash join
- Hello world/Newbie
- Hickerson series of almost integers
- Hilbert curve
- Hofstadter-Conway $10,000 sequence
- Hofstadter Figure-Figure sequences
- Hofstadter Q sequence
- Home primes
- Honeycombs
- Horner's rule for polynomial evaluation
- Hough transform
- Huffman coding
- Hunt the Wumpus

### I

- IBAN
- ISBN13 check digit
- Idiomatically determine all the characters that can be used for symbols
- Image convolution
- Imaginary base numbers
- Increasing gaps between consecutive Niven numbers
- Index finite lists of positive integers
- Integer overflow
- Intersecting number wheels
- Introspection
- Iterated digits squaring

### J

### K

- K-d tree
- K-means++ clustering
- Kaprekar numbers
- Kernighans large earthquake problem
- 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
- Kronecker product
- Kronecker product based fractals

### L

- LU decomposition
- LZW compression
- Lah numbers
- Langton's ant
- Largest proper divisor of n
- 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 common subsequence
- Longest increasing subsequence
- Longest string challenge
- Lucas-Lehmer test
- Lucky and even lucky numbers
- Luhn test of credit card numbers
- Lychrel numbers

### M

- Machine code
- Mad Libs
- Magic constant
- Magic squares of doubly even order
- Magic squares of singly even order
- Magnanimous numbers
- Main step of GOST 28147-89
- Mastermind
- Matrix chain multiplication
- Matrix digital rain
- Maximum triangle path sum
- Mayan calendar
- Mayan numerals
- McNuggets problem
- Median filter
- Memory layout of a data structure
- Merge and aggregate datasets
- Metallic ratios
- Metaprogramming
- Metered concurrency
- Mian-Chowla sequence
- Miller–Rabin primality test
- Mind boggling card trick
- 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
- Modified random distribution
- Modular arithmetic
- Monads/Writer monad
- Monte Carlo methods
- Motzkin numbers
- Move-to-front algorithm
- Multi-base primes
- Multi-dimensional array
- Multifactorial
- Multiple regression
- Multiplicative order
- Munching squares
- Möbius function

### N

- Narcissist
- Narcissistic decimal number
- Natural sorting
- Nautical bell
- Negative base numbers
- Nested templated data
- Nim game
- Non-continuous subsequences
- Non-decimal radices/Convert
- Non-decimal radices/Input
- Non-decimal radices/Output
- Non-transitive dice
- Nonoblock
- Nonogram solver
- Number reversal game
- Numbers which are not the sum of distinct squares
- 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
- Palindrome dates
- Palindromic gapful numbers
- Pancake numbers
- Paraffins
- Parameterized SQL statement
- Parametric polymorphism
- Parse an IP Address
- Parsing/RPN calculator algorithm
- Parsing/RPN to infix conversion
- Parsing/Shunting-yard algorithm
- Partial function application
- Particle fountain
- Partition an integer x into n primes
- Pascal's triangle/Puzzle
- Password generator
- Peaceful chess queen armies
- Peano curve
- Pell numbers
- Penney's game
- Pentomino tiling
- Percentage difference between images
- Percolation/Bond percolation
- Percolation/Mean cluster density
- Percolation/Mean run density
- Percolation/Site percolation
- Periodic table
- Peripheral drift illusion
- Permutations/Derangements
- Permutations/Rank of a permutation
- Permutations by swapping
- Pernicious numbers
- Phrase reversals
- Pig the dice game/Player
- Pinstripe/Display
- Pinstripe/Printer
- Pisano period
- Plasma effect
- Playfair cipher
- Poker hand analyser
- Polynomial regression
- Polyspiral
- Pragmatic directives
- Primality by Wilson's theorem
- Prime conspiracy
- Prime triangle
- 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/Splitmix64
- Pythagoras tree
- Pythagorean quadruples

### R

- RCRPG
- Ramanujan's constant
- Ramanujan primes/twins
- Ramer-Douglas-Peucker line simplification
- Random Latin squares
- Random sentence from book
- Range consolidation
- Ranking methods
- Rare numbers
- Ray-casting algorithm
- Recaman's sequence
- Record sound
- Reduced row echelon form
- Reflection/Get source
- Reflection/List methods
- Reflection/List properties
- Rendezvous
- Repunit primes
- Resistor mesh
- Respond to an unknown method call
- Retrieve and search chat history
- Rhonda numbers
- Rock-paper-scissors
- Rosetta Code/Count examples
- Rosetta Code/Find bare lang tags
- Rosetta Code/Find unimplemented tasks
- Rosetta Code/Rank languages by number of users
- Runge-Kutta method
- Runtime evaluation
- Runtime evaluation/In an environment
- Ruth-Aaron numbers

### S

- S-expressions
- 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
- Search in paragraph's text
- Selectively replace multiple instances of a character within a string
- 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
- Sequence of primorial primes
- Set consolidation
- Set puzzle
- Set right-adjacent bits
- Seven-sided dice from five-sided dice
- Shoelace formula for polygonal area
- Shortest common supersequence
- Sierpinski arrowhead curve
- Sierpinski pentagon
- Sierpinski square curve
- Sierpinski triangle/Graphical
- Simple database
- Simple turtle graphics
- Simulate input/Keyboard
- Simulate input/Mouse
- Sleeping Beauty problem
- Smallest number k such that k+2^m is composite for all m less than k
- Smarandache prime-digital sequence
- 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 disjoint sublist
- Sort numbers lexicographically
- Sort stability
- Sort three variables
- Sorting algorithms/Cocktail sort with shifting bounds
- Sorting algorithms/Pancake sort
- Sorting algorithms/Patience sort
- Sorting algorithms/Permutation sort
- Sorting algorithms/Quicksort
- Sorting algorithms/Radix sort
- Sorting algorithms/Stooge sort
- Sorting algorithms/Strand sort
- Special characters
- Special variables
- Speech synthesis
- Spelling of ordinal numbers
- Spinning rod animation/Text
- Spiral matrix
- Split a character string based on change of character
- Square-free integers
- Square form factorization
- 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
- Strassen's algorithm
- Stream merge
- String comparison
- Strip control codes and extended characters from a string
- Strong and weak primes
- Substitution cipher
- Subtractive generator
- Sudan function
- Suffixation of decimal numbers
- Sum and product puzzle
- Sum of elements below main diagonal of matrix
- Summarize and say sequence
- Summarize primes
- Super-d numbers
- Superellipse
- Sutherland-Hodgman polygon clipping
- Sylvester's sequence

### T

- Table creation/Postal addresses
- Tarjan
- Teacup rim text
- Terminal control/Coloured text
- Terminal control/Cursor movement
- Terminal control/Cursor positioning
- 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/Unicode output
- Test integerness
- Text processing/1
- Text processing/2
- Text processing/Max licenses in use
- The Name Game
- The Twelve Days of Christmas
- The sieve of Sundaram
- Thiele's interpolation formula
- Tic-tac-toe
- Time a function
- Tokenize a string with escaping
- Tonelli-Shanks algorithm
- Top rank per group
- Topological sort
- Topswops
- Total circles area
- Trabb Pardo–Knuth algorithm
- Tree datastructures
- Tree from nesting levels
- Tree traversal
- Trigonometric functions
- Truncatable primes
- Truth table
- Twelve statements
- Two's complement
- Two bullet roulette

### U

### V

- Validate International Securities Identification Number
- Vampire number
- Van der Corput sequence
- Variable-length quantity
- Variable declaration reset
- Variable size/Set
- Verhoeff algorithm
- Verify distribution uniformity/Chi-squared test
- Verify distribution uniformity/Naive
- Video display modes
- Vigenère cipher
- Vigenère cipher/Cryptanalysis
- Vogel's approximation method

### 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 Delphi (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
- ADFGVX cipher
- Addition-chain exponentiation
- Addition chains
- Air mass
- Alternade words
- Anadromes
- Anagram generator
- Append numbers at same position in strings
- Arithmetic coding/As a generalized change of radix
- Arithmetic derivative
- Aspect oriented programming
- Assertions in design by contract
- Audio frequency generator
- Autogram checker

### B

- B-spline
- Babylonian spiral
- Bacon cipher
- Banker's algorithm
- Base58Check encoding
- Base 16 numbers needing a to f
- Bifid cipher
- Bilinear interpolation
- Binary coded decimal
- Bioinformatics/Global alignment
- Bioinformatics/Subsequence
- Black box
- Blackjack strategy
- Boids
- Boyer-Moore string search
- Brace expansion using ranges

### C

- CLI-based maze-game
- Camel case and snake case
- Card shuffles
- Changeable words
- Chebyshev coefficients
- Checksumcolor
- Chess player
- Cipolla's algorithm
- Code Golf: Code Golf
- 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/Preprocessor
- 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)
- Coprimes
- Count how many vowels and consonants occur in a string
- Count the coins/0-1
- 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
- Cycles of a permutation

### D

- Data Encryption Standard
- Dating agency
- Day of the week of Christmas and New Year
- Decision tables
- 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

### E

### F

- Fibonacci heap
- Fibonacci matrix-exponentiation
- Find adjacent primes which differ by a square integer
- Find first missing positive
- Find minimum number of coins that make a given value
- Find square difference
- Find squares n where n+1 is prime
- Find words which contain the most consonants
- Find words which contains more than 3 e vowels
- Find words whose first and last three letters are equal
- Find words with alternating vowels and consonants
- First 9 prime Fibonacci number
- Four sides of square
- Free polyominoes enumeration
- Frobenius numbers

### G

### I

### L

- Largest difference between adjacent primes
- Largest five adjacent number
- Largest palindrome product
- Largest prime factor
- Largest product in a grid
- Last list item
- Launch rocket with countdown and acceleration in stdout
- Line circle intersection
- Linux CPU utilization
- Logistic curve fitting in epidemiology
- Long stairs
- Longest common prefix
- Longest palindromic substrings
- Longest substrings without repeating characters

### M

- 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
- Modulinos
- Montgomery reduction
- Morpion solitaire
- Mosaic matrix
- Most frequent k chars distance
- Multidimensional Newton-Raphson method
- Multiline shebang
- Multiton

### N

- N-body problem
- N-queens minimum and knights and bishops
- NYSIIS
- Native shebang
- Neighbour primes
- Next special primes
- Nice primes
- 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 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

### P

- Palindromic primes
- Palindromic primes in base 16
- Pan base non-primes
- Parse EBNF
- Particle swarm optimization
- Penrose tiling
- Permutations with repetitions
- Permutations with some identical elements
- Permuted multiples
- Piprimes
- Polynomial derivative
- Positive decimal integers with the digit 1 occurring exactly twice
- Powerful 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 triplets
- Prime words
- Primes which contain only one odd digit
- Primes whose first and last number is 3
- Primes with digits in nondecreasing order
- Process SMIL directives in XML data
- Product of divisors
- Proof

### R

- Railway circuit
- 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
- 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
- Show the (decimal) value of a number of 1s appended with a 3, then squared
- Sierpinski curve
- Simulated annealing
- Singly-linked list/Element removal
- 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 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 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
- Summation of 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 to HTML
- 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
- Two identical strings
- Type detection

### U

### W

## Requiring Attention[edit]

### Examples[edit]

These tasks have implementations in Delphi, 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 Delphi 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 Delphi 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.