# Reports:Tasks not implemented in PHP

**Awareness**

If

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

## Contents

## Not implemented[edit]

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

### A

- AKS test for primes
- ASCII art diagram converter
- AVL tree
- Abbreviations, automatic
- Abbreviations, simple
- Abelian sandpile model
- Abelian sandpile model/Identity
- Abundant, deficient and perfect number classifications
- Abundant odd numbers
- Active object
- Additive primes
- Aliquot sequence classifications
- Almkvist-Giullera formula for pi
- Almost prime
- Amb
- Angle difference between two bearings
- Angles (geometric), normalization and conversion
- Anti-primes
- Apply a digital filter (direct form II transposed)
- Approximate equality
- Archimedean spiral
- Arena storage pool
- Arithmetic-geometric mean/Calculate Pi
- Arithmetic/Complex
- Arithmetic/Rational
- Arithmetic evaluation
- Atomic updates
- Average loop length
- Averages/Simple moving average

### B

- Balanced ternary
- Barnsley fern
- Bell numbers
- Benford's law
- Bernoulli numbers
- Bin given limits
- Binary strings
- Bioinformatics/Sequence mutation
- Bioinformatics/base count
- Biorhythms
- Bitcoin/public point to address
- Bitmap/Bresenham's line algorithm
- Bitmap/Bézier curves/Quadratic
- Bitmap/Flood fill
- Bitmap/Midpoint circle algorithm
- Bitmap/PPM conversion through a pipe
- Bitmap/Read a PPM file
- Bitmap/Read an image through a pipe
- Bitwise IO
- Box the compass
- Brazilian numbers
- Brownian tree
- Bulls and cows/Player
- Burrows–Wheeler transform

### C

- Calculating the value of e
- Calendar
- Calkin-Wilf sequence
- Call a foreign-language function
- Call a function
- Call a function in a shared library
- Canonicalize CIDR
- Cantor set
- Carmichael 3 strong pseudoprimes
- Cartesian product of two or more lists
- Case-sensitivity of identifiers
- Casting out nines
- Catalan numbers/Pascal's triangle
- Catamorphism
- Catmull–Clark subdivision surface
- Chaocipher
- Chaos game
- Chat server
- Check Machin-like formulas
- Check input device is a terminal
- Checkpoint synchronization
- Chernick's Carmichael numbers
- Cheryl's birthday
- Chinese remainder theorem
- Chinese zodiac
- Cholesky decomposition
- Chowla numbers
- Circles of given radius through two points
- Circular primes
- Cistercian numerals
- Closest-pair problem
- Color quantization
- Color wheel
- Colour pinstripe/Display
- Colour pinstripe/Printer
- Combinations and permutations
- Commatizing numbers
- Compare a list of strings
- Compare length of two strings
- Compare sorting algorithms' performance
- Compile-time calculation
- Compiler/AST interpreter
- Compiler/code generator
- Compiler/lexical analyzer
- Compiler/syntax analyzer
- Compiler/virtual machine interpreter
- Concurrent computing
- 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 seconds to compound duration
- Convex hull
- Conway's Game of Life
- Copy stdin to stdout
- Count in factors
- Count the coins
- Cramer's rule
- Create a file on magnetic tape
- Create a two-dimensional array at runtime
- Create an object at a given address
- Cuban primes
- Currency
- Cut a rectangle
- Cyclotomic polynomial

### D

- De Bruijn sequences
- Death Star
- Deconvolution/1D
- Deconvolution/2D+
- Define a primitive data type
- Deming's Funnel
- Determinant and permanent
- Determine if a string has all the same characters
- Determine if a string has all unique characters
- Determine if only one instance is running
- Determine if two triangles overlap
- Determine sentence type
- Dice game probabilities
- Digital root
- Digital root/Multiplicative digital root
- Dinesman's multiple-dwelling problem
- Dining philosophers
- Display a linear combination
- Display an outline as a nested table
- Distributed programming
- Diversity prediction theorem
- Doubly-linked list/Definition
- Doubly-linked list/Element definition
- Doubly-linked list/Element insertion
- Doubly-linked list/Traversal
- Dragon curve
- Draw a clock
- Draw a cuboid
- Draw a pixel
- Draw a rotating cube
- Draw a sphere
- Dutch national flag problem

### E

- EKG sequence convergence
- Eban numbers
- Eertree
- Egyptian division
- 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
- Esthetic numbers
- Euler's constant 0.5772...
- Euler's identity
- Euler method
- Events
- Exceptions/Catch an exception thrown in a nested call
- Executable library
- Execute HQ9+
- Execute SNUSP
- Exponentiation operator
- Exponentiation order
- Exponentiation with infix operators in (or operating on) the base
- Extend your language
- Extensible prime generator
- Extreme floating point values

### F

- FASTA format
- 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
- Feigenbaum constant calculation
- Fermat numbers
- Fibonacci word
- Fibonacci word/fractal
- File size distribution
- 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
- First power of 2 that has leading decimal digits of 12
- Five weekends
- Fivenum
- Fixed length records
- Flipping bits game
- Formal power series
- Fortunate numbers
- Four bit adder
- Four is magic
- Four is the number of letters in the ...
- Fraction reduction
- Fractran
- French Republican calendar
- Function frequency
- Function prototype
- 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
- Generate Chess960 starting position
- Generate random chess position
- Get system command output
- Globally replace text in several files
- Go Fish
- Graph colouring
- Greyscale bars/Display
- Guess the number/With feedback (player)

### H

- HTTPS/Authenticated
- HTTPS/Client-authenticated
- Halt and catch fire
- Hamming numbers
- Harshad or Niven series
- Heronian triangles
- Hickerson series of almost integers
- Hilbert curve
- History variables
- Hofstadter-Conway $10,000 sequence
- Hofstadter Figure-Figure sequences
- Hofstadter Q sequence
- Holidays related to Easter
- Honeycombs
- Horizontal sundial calculations
- Host introspection
- Hough transform
- Humble numbers
- Hunt the Wumpus

### I

- ISBN13 check digit
- 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
- Image noise
- Imaginary base numbers
- Increasing gaps between consecutive Niven numbers
- Index finite lists of positive integers
- Inheritance/Multiple
- Integer overflow
- Integer sequence
- Interactive programming
- Intersecting number wheels
- Inverted syntax
- Isqrt (integer square root) of X
- Iterated digits squaring

### J

### K

- K-d tree
- K-means++ clustering
- Keyboard input/Flush the keyboard buffer
- Keyboard input/Keypress check
- Keyboard input/Obtain a Y or N response
- Keyboard macros
- Knapsack problem/Bounded
- Knapsack problem/Unbounded
- Knight's tour
- Knuth's power tree
- Koch curve
- Kolakoski sequence
- Kosaraju
- Kronecker product
- Kronecker product based fractals

### L

- LU decomposition
- Lah numbers
- Largest number divisible by its digits
- Largest proper divisor of n
- 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
- Long literals, with continuations
- Long primes
- Longest common subsequence
- Longest common substring
- Loops/Increment loop index within loop body
- Loops/With multiple ranges
- Loops/Wrong ranges
- Lucas-Lehmer test
- Lucky and even lucky numbers
- Ludic numbers
- Lychrel numbers

### M

- MAC Vendor Lookup
- MD5/Implementation
- Machine code
- Mad Libs
- Magic squares of doubly even order
- Magic squares of odd order
- Magic squares of singly even order
- Magnanimous numbers
- Main step of GOST 28147-89
- Make directory path
- Map range
- Mastermind
- Matrix-exponentiation operator
- Matrix chain multiplication
- Matrix digital rain
- Matrix multiplication
- Maximum triangle path sum
- Mayan calendar
- Mayan numerals
- Maze solving
- McNuggets problem
- Median filter
- Memory allocation
- Memory layout of a data structure
- Merge and aggregate datasets
- Mertens function
- Metallic ratios
- Metaprogramming
- Metered concurrency
- Metronome
- Mian-Chowla sequence
- Mind boggling card trick
- Minimal steps down to 1
- Minimum positive multiple in base 10 using only 0 and 1
- Minkowski question-mark function
- Modified random distribution
- Modular arithmetic
- Monads/List monad
- Monads/Maybe monad
- Morse code
- Motzkin numbers
- Multi-dimensional array
- Multifactorial
- Multiple distinct objects
- Multiple regression
- Multiplication tables
- Multiplicative order
- Multisplit
- Musical scale
- Mutex
- Möbius function

### N

- N-smooth numbers
- Naming conventions
- Narcissist
- Narcissistic decimal number
- Natural sorting
- Nautical bell
- Negative base numbers
- Nested templated data
- Next highest int from digits
- Nim game
- Nimber arithmetic
- Non-continuous subsequences
- Non-transitive dice
- Nonoblock
- Nonogram solver
- Numbers with equal rises and falls
- Numeric error propagation
- Numerical and alphabetical suffixes
- Numerical integration
- Numerical integration/Gauss-Legendre Quadrature

### 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
- Parallel calculations
- Parametric polymorphism
- Parse an IP Address
- 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
- Pascal matrix generation
- Password generator
- Pathological floating point problems
- Pattern matching
- Peaceful chess queen armies
- Peano curve
- Pell's equation
- Penney's game
- Pentagram
- Pentomino tiling
- Percentage difference between images
- Percolation/Bond percolation
- Percolation/Mean cluster density
- Percolation/Mean run density
- Percolation/Site percolation
- Perfect shuffle
- Perfect totient numbers
- Peripheral drift illusion
- Perlin noise
- Permutation test
- Permutations
- Permutations/Derangements
- Permutations/Rank of a permutation
- Permutations by swapping
- Pernicious numbers
- Pi
- Pierpont primes
- Pig the dice game/Player
- Pinstripe/Display
- Pinstripe/Printer
- Pisano period
- Plasma effect
- Playfair cipher
- Plot coordinate pairs
- Poker hand analyser
- Polynomial long division
- Polynomial regression
- Polyspiral
- Pragmatic directives
- Price fraction
- Primality by Wilson's theorem
- Prime conspiracy
- Prime decomposition
- Primes - allocate descendants to their ancestors
- Primorial numbers
- 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
- Pythagorean quadruples

### R

- RCRPG
- RIPEMD-160
- RSA code
- Ramanujan's constant
- Ramanujan primes/twins
- Random Latin squares
- Random number generator (device)
- Random sentence from book
- Range consolidation
- Range extraction
- Ranking methods
- Rare numbers
- Rate counter
- Read a file character by character/UTF8
- Record sound
- Reflection/Get source
- Remove lines from a file
- Rendezvous
- Rep-string
- Repeat
- Resistor mesh
- Retrieve and search chat history
- 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 number of users
- Rosetta Code/Rank languages by popularity
- Runge-Kutta method

### S

- S-expressions
- SHA-256 Merkle tree
- Safe addition
- Safe primes and unsafe primes
- Sailors, coconuts and a monkey problem
- Same fringe
- Scope/Function names and labels
- Scope modifiers
- Self numbers
- Semiprime
- 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 primes by trial division
- Sequence of primorial primes
- Set
- Set consolidation
- Set of real numbers
- Set puzzle
- Set right-adjacent bits
- Seven-sided dice from five-sided dice
- Sexy primes
- Shoelace formula for polygonal area
- Short-circuit evaluation
- Shortest common supersequence
- Sierpinski arrowhead curve
- Sierpinski pentagon
- Sierpinski square curve
- Sierpinski triangle/Graphical
- Simple database
- Singly-linked list/Element definition
- Singly-linked list/Element insertion
- Singly-linked list/Traversal
- Sleeping Beauty problem
- Smarandache prime-digital sequence
- Smith numbers
- 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 array of composite structures
- Sort an outline at every level
- Sort disjoint sublist
- Sort numbers lexicographically
- Sorting Algorithms/Circle Sort
- Sorting algorithms/Cocktail sort with shifting bounds
- Sorting algorithms/Heapsort
- Sorting algorithms/Pancake sort
- Sorting algorithms/Radix sort
- Sorting algorithms/Sleep sort
- Sparkline in unicode
- Special characters
- Special variables
- Spelling of ordinal numbers
- Spinning rod animation/Text
- Spiral matrix
- Split a character string based on change of character
- Square-free integers
- Square but not cube
- Square form factorization
- Stable marriage problem
- 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
- Strassen's algorithm
- Stream merge
- String append
- String comparison
- String prepend
- Strip comments from a string
- Strip control codes and extended characters from a string
- Strong and weak primes
- Subleq
- Subtractive generator
- Successive prime differences
- Suffixation of decimal numbers
- Sum and product puzzle
- Sum of elements below main diagonal of matrix
- Sum to 100
- Summarize and say sequence
- Summarize primes
- Super-d numbers
- Superellipse
- Superpermutation minimisation
- Sylvester's sequence
- Synchronous concurrency

### T

- Tarjan
- Tau function
- Tau number
- Taxicab numbers
- Teacup rim text
- Terminal control/Clear the screen
- Terminal control/Coloured 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/Unicode output
- Test a function
- Test integerness
- Text processing/1
- Textonyms
- The ISAAC Cipher
- The Name Game
- The sieve of Sundaram
- Thiele's interpolation formula
- Time a function
- Tokenize a string with escaping
- Tonelli-Shanks algorithm
- Topic variable
- Topological sort
- Topswops
- Total circles area
- Totient function
- Trabb Pardo–Knuth algorithm
- Tree datastructures
- Tree from nesting levels
- Truncatable primes
- Truncate a file
- Truth table
- Twelve statements
- Twin primes
- Two bullet roulette

### U

### V

- Validate International Securities Identification Number
- Vampire number
- Van Eck sequence
- Van der Corput sequence
- Variable-length quantity
- Variable size/Get
- Variable size/Set
- Vector
- Verhoeff algorithm
- Verify distribution uniformity/Chi-squared test
- Verify distribution uniformity/Naive
- Video display modes
- Vigenère cipher/Cryptanalysis
- 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 PHP (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 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/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
- Count the coins/0-1
- Cousin primes
- 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
- Cyclops numbers

### 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
- 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
- Dominoes
- Doomsday rule
- Doubly-linked list/Element removal
- Draw pixel 2

### E

### F

- Fibonacci heap
- Fibonacci matrix-exponentiation
- 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 which contains more than 3 e vowels
- Find words whose first and last three letters are equal
- Find words with alternating vowels and consonants
- Finite state machine
- 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
- Length of an arc between two angles
- Line circle intersection
- Linux CPU utilization
- Logistic curve fitting in epidemiology
- Long stairs
- Longest common prefix
- Longest common suffix
- Longest palindromic substrings
- Longest substrings without repeating characters

### M

- Magic constant
- Make a backup file
- Maximum difference between adjacent elements of list
- Minimum number of cells after, before, above and below NxN squares
- Minimum numbers of three lists
- Minimum primes
- Montgomery reduction
- Morpion solitaire
- Most frequent k chars distance
- Multi-base primes
- Multidimensional Newton-Raphson method
- Multiline shebang
- Multiton

### N

- N-body problem
- NYSIIS
- Names to numbers
- 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 are not the sum of distinct squares
- 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
- Pandigital prime
- Parse EBNF
- Parse command-line arguments
- Particle fountain
- 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 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 whose 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
- 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
- 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
- Round-robin tournament schedule
- 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
- Shift list elements to left by 3
- Show the (decimal) value of a number of 1s appended with a 3, then squared
- Sierpinski curve
- Simple turtle graphics
- Simulated annealing
- Sine wave
- Singly-linked list/Element removal
- Smallest enclosing circle problem
- Smallest multiple
- Smallest number k such that k+2^m is composite for all m less than k
- 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 triangle solitare puzzle
- Solving coin problems
- Sort the letters of string in alphabetical order
- Sorting algorithms/Cycle sort
- 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 numbers
- Strange plus numbers
- Strange unique prime triplets
- Subset sum problem
- Substring primes
- Suffix tree
- Sum data type
- Sum of divisors
- 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
- 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 completion
- Text to HTML
- Three word location
- Time-based one-time password algorithm
- Topological sort/Extracted top item
- Transportation problem
- Triplet of three numbers
- Tropical algebra overloading
- Two identical strings
- Two sum

### U

- URL shortener
- Ulam numbers
- Ultra useful primes
- Unicode polynomial equation
- Unique characters
- Unique characters in each string
- Unit testing
- Uno (Card Game)
- Untrusted environment
- Useless instructions
- User defined pipe and redirection operators
- Using a speech engine to highlight words
- Using the Meetup.com API

### W

## Requiring Attention[edit]

### Examples[edit]

These tasks have implementations in PHP, 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 PHP 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 PHP 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.