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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.

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a sequence of well-defined steps that defines an abstract solution to a problem. Use this tag when your issue is related to design and analysis of algorithms.
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Questions related to the (computational) complexity of solving problems
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Questions about graphs, discrete structures of nodes which are connected by edges. Popular flavors are trees and networks with edge capacity.
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Questions related to formal languages, grammars, and automata theory
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Questions about Turing machines, a theoretical model of mechanical computation capable of simulating any computer program.
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Questions about the science and art of determining properties of algorithms, often including correctness, runtime and space usage. Use the [runtime-analysis] tag for questions about the runtime of al…
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Questions about ways of storing data so that it can be used advantageously by algorithms.
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Questions related to computability theory, a.k.a. recursion theory
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The amount of time resources (number of atomic operations or machine steps) required to solve a problem expressed in terms of input size. If your question concerns algorithm analysis, use [tag:runti…
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Questions about mathematical devices that read an input stream symbol by symbol and use a state transition map to produce an output stream, maybe using secondary storage.
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Questions about problems that entail selecting the best element from some set of available alternatives, and methods to solve them.
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Questions about properties of the class of regular languages and individual languages.
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Questions about the set of languages (equivalently) described by context-free grammars or accepted by (non-deterministic) pushdown automata.
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Questions about finite automata, an elementary automaton model with finite memory. It is equivalent to regular languages and the basis for many more complex models.
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Questions about the hardest problems in NP, i.e. of those that can be solved in polynomial time by nondeterministic Turing machines.
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Questions about asymptotic notations and analysis
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Questions about how specific notions have to be understood as well as conventions of notation.
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Questions about computer algorithms that automatically discover patterns in data and make good decisions based on them.
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Questions about formal grammars, generative descriptions of formal languages.
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In computability and complexity, finding mappings between problems that allow solving one problem using a solution of another one. For reduction in programming language theory (e.g. beta-reduction), s…
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Questions requesting papers in the literature on specific, narrow issues.
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Questions about the organization and design of computer hardware.
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Questions about methods for estimating the increase in runtime of an algorithm as the input size increases.
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Questions related to design, implementation, and analysis of programming languages. NOT for questions about how to program, which are off-topic on this site.
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Questions related to mathematical logic and its use in computer science
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the algorithmic problem of ordering a set of elements with respect to some ordering relation.
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Questions about problems which cannot be solved by any Turing machine.
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Questions about algorithmic solutions of geometric problems, or other algorithms making usage of geometry.
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Questions about a special kind of graphs, namely connected and cycle-free ones.
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Questions about problems that can be solved by combining recursively obtained solutions of subproblems.
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Questions about the principles of software that interfaces between hardware and applications.
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Questions about regular expressions, a formalism to describe regular languages.
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Questions about general methods and techniques for proving multiple theorems. When asking about the proof of a single statement, use tags relating to what the proof is about instead.
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Questions related to combinatorics and discrete mathematical structures
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at least as hard as NP-complete problems
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Algorithms for finding an element in some specified data-structure (most commonly, in a tree).