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.
Code-golf is a competition to solve a particular problem in the fewest bytes of source code.
A competition to solve a particular problem through the usage and manipulation of strings.
The challenge involves mathematics in some central way. Also consider using more specific tags, listed in the tag wiki info.
A competition to solve a particular problem through the usage and manipulation of numbers.
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.
A code challenge is 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).
For challenges involving sequences, typically of numbers following some pattern.
A competition to solve a particular problem through the usage and manipulation of arrays.
For challenges which involve deciding whether or not the input meets certain criteria, and outputting some data, representing that decision.
Kolmogorov complexity, informally, is 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…
Challenges related to elementary arithmetic.
Number theory involves properties and relationships of numbers, primarily positive integers.
For challenges involving the manipulation of integers.
A popularity-contest is 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 involving a grid.
For challenges involving combinatorics.
This challenge is intended to be solved by using, manipulating, or creating shapes or other geometric structures.
For questions asking for tips on golfing in a specific language, doing well in certain challenge tag, or improving a particular piece of code.
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…
Tasks involving random numbers and/or output.
Imposes a restriction on the source code used to solve the challenge, for example, having no numbers in the source code.
For challenges about identifying and manipulating prime numbers
This challenge is generally based upon, related to, or simulates a game or some portion of one.
for challenges involving matrices. A matrix, also known as a 2D array, is a list of numbers arranged in a rectangle with rows and columns.
This challenge is intended to be solved by using, manipulating, accepting as input, outputting, or calculating calendar dates or clock times.
A quine is a program which produces its source as output. This tag indicates that the challenge is related to quines.
denotes challenges where parsing input is a large / the main part of the challenge.
For challenges about binary, or the base 2 number system.
This challenge is intended to be solved by sorting, ordering, or otherwise organizing some set of data.
For challenges regarding graphs, mathematical structures used to model relations between objects.
A permutation is a particular ordering of some list of objects. Problems tagged with permutation usually involve finding or generating permutations, including anagrams of text.
The winner of a fastest-code challenge is determined by the runtime performance of the submissions. For fairness, all submissions should be benchmarked on the same machine, which usually means all sub…
For challenges that involve the physical layout or physical manipulation of source-code.
Conversion of numbers between positional numeral systems. Most common systems are decimal, binary, hexadecimal etc.
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…
For challenges which consist of two adversary (and asymmetric) sub-challenges.