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.
a competition to solve a particular problem in the fewest bytes of source code. If you want to score by characters instead of bytes, please state this explicitly in the challenge. If sour…
A competition to solve a particular problem through the usage and manipulation of strings.
The challenge involves mathematics. Also consider using more specific tags: [number] [number-theory] [arithmetic] [combinatorics] [graph-theory] [geometry] [abstract-algebra].
This challenge involves creating or parsing pictures using text characters as the paint. Typically this uses only 95 printable (from a total of 128) characters defined by the ASCII Standard from 1963.
intended to be solved by using, manipulating, accepting as input, or outputting numeric values.
a competition for creative ways to solve a programming puzzle with an objective winning criterion not covered by other scoring tags (e.g. code-golf).
the amount of code it takes to describe or produce a constant object, such as a string or image. When posting a challenge in this category, please make sure it ad…
A competition to solve a particular problem through the usage and manipulation of arrays.
a competition where the answer with the highest vote tally (upvotes minus downvotes) wins. As these are frequently closed, read the tag info and post your challenge to the sand…
For challenges which involve deciding whether or not the input meets certain criteria, and outputting some data, representing that decision.
Number theory involves properties and relationships of numbers, primarily positive integers.
This challenge involves drawing pictures on a screen or generating image files. For pure ASCII art contests, use [ascii-art] instead. If participants can choose between graphics and ASCII art, use bot…
Imposes a restriction on the source code used to solve the challenge, for example, having no numbers in the source code.
intended to be solved by using, manipulating, or creating shapes or other geometric structures.
For questions asking for tips on a specific piece of code, to make it a better answer to a programming challenge that is on-topic on this site. Tag [tips] questions with other appropriate tags, s…
generally based upon, related to, or simulates a game or some portion of one.
For challenges involving the manipulation of integers.
a program which produces its source as output. This tag indicates that the challenge is related to quines.
intended to be solved by using, manipulating, accepting as input, outputting, or calculating calendar dates or clock times.
denotes challenges where parsing input is a large / the main part of the challenge.
intended to be solved by sorting, ordering, or otherwise organizing some set of data.
a list of numbers arranged in a rectangle with rows and columns. In programming, it is also known as a 2D array. Use this tag if your challenge is about manipulating matrices.
the base 2 number system. Use this tag for challenges involving base 2.
a particular ordering of some list of objects. Problems tagged with permutation usually involve finding or generating permutations, including anagrams of text.
Conversion of numbers between positional numeral systems. Most common systems are decimal, binary, hexadecimal etc.
For challenges regarding graphs, mathematical structures used to model relations between objects.
determined by the runtime performance of the submissions. For fairness, all submissions should be benchmarked on the same machine, which usually means all sub…
King-of-the-hill indicates a game where the submissions interact with and compete against each other in some form of game. Competitions which pit programs against each other without interaction should…
These challenges involve processing pre-existing image files, by altering them in some way, gathering statistics, or other image processing tasks.