A tag is a keyword or label that categorizes your question with other, similar questions. Using the right tags makes it easier for others to find and answer your question.
This challenge is related to the Python language. Note that challenges that require the answers to be in a specific language are generally discouraged.
Problems in geometry or graph theory that involve finding an optimal (e.g. shortest) path, subject to constraints (obstacles).
These challenges involve processing pre-existing image files, by altering them in some way, gathering statistics, or other image processing tasks.
Problems involving processing of natural languages in a human way. Tasks include interpreting free text, correcting spelling or grammar, understanding pronunciation, etc.
For challenges focusing on the optimization of an aspect not covered by other tags. (not a winning criterion)
Tasks involving writing interpreters for various languages or formalisms.
The challenge involves Fibonacci numbers or one of their generalizations.
For challenges regarding counting the number of occurrences of some characteristic.
Chess is a strategic game played with two players on a checkered grid. This tag is for challenges related to chess or any variation on chess.
Challenges pertaining to a sequence within a larger sequence
For challenges involving code that runs in multiple programming languages.
In a balanced string certain pairs of characters or substrings always appear with the same amount. Often there are additional restrictions that those pairs also have to be ordered. The most common exa…
For challenges where an exact output is not required but some property must still be fulfilled.
if your challenge is about writing programs that solve puzzles such as Sudoku, Rubik's Cube, Crossword puzzles, etc.
Palindromes are words, phrases, representations of numbers or times which read the same in reverse, for example "level", "reviver", "12321", "10:01". See also the [balanced-string] tag.
This challenge involves the manipulation of rational numbers, i.e. those which can be represented as a fraction of integers. Do not use this tag if rational numbers are just one of several admissible …
Code challenges that involve the use of regular expressions.
indicates that the challenge requires answers to use the Internet to retrieve information.
Related to compressing or decompressing arbitrary data. Challenges which relate to compressing a single specific input should instead be tagged [kolmogorov-complexity]
For challenges where answers are expected to generate code.
For challenges with a restriction on the amount of time a submission is allowed to use.
For challenges involving unicode.
A challenge that involves making a "Hello, World!" program, or other similar strings. It is recommended to avoid using exactly "Hello, World!" as many languages have builtins to print it, trivialising…
For challenges involving polynomials, mathematical expressions that consist of variables and coefficients.
For challenges involving the usage and manipulation of the alphabet.
For challenges which involve card games. This includes playing the game, implementing the game, as well as challenges concerned with individual mechanics and analysis of the game (for instance, comput…
Atomic code golf is scored by the number of operations in a specific fragment of a language you define.
This challenge is related to the BF language. Note that challenges that require the answers to be in a specific language are generally discouraged.
indicates that the challenge involves converting from one format to another.
Challenges with a spec which requires all answers to meet certain time complexity restrictions. This could be specific ("Your answer must be O(n^2) where n is the number of items in the input"), or at…
for challenges involving board games.
Challenges relating to the 95 printable ASCII characters (space to ~). Tabs and newlines may be included as well, depending on the challenge.
Fastest-algorithm competitions are won by the answer with the smallest asymptotic time complexity. For challenges based on actual runtime, use [fastest-code] instead.
For challenges involving bitwise commands or manipulation of numbers at the bit level
indicates that the challenge involves music, e.g. taking music as input, producing music as output or handling musical notes.