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.

P versus NP and other resource-bounded computation.
Questions regarding well-defined instructions for completing a task, and relevant analysis in terms of time/memory/etc.
1813 questions
Reference-request is used when the author needs to know about work related to the question.
Graph theory is the study of graphs, mathematical structures used to model pairwise relations between objects.
1534 questions
Algorithms on graphs, excluding heuristics.
1032 questions
Questions related to NP-hardness and NP-completeness.
715 questions
Computational complexity classes and their relations
Questions related to combinatorics and discrete mathematical structures
666 questions
Computational and mathematical logic.
540 questions
Questions about approximation algorithms.
513 questions
formal languages, grammars, automata theory
441 questions
general questions about selecting a best element from some set of available alternatives.
440 questions
Automata Theory, including abstract machines, grammars, parsing, grammatical inference, transducers, and finite-state techniques
416 questions
A soft question is a question (possibly subjective) about the field of theoretical computer science as opposed to being a question in theoretical computer science.
411 questions
Quantum computation and computational issues related to quantum mechanics
398 questions
Computability theory a.k.a. recursion theory.
397 questions
Time complexity of decision problems or relations among time-bounded complexity classes. (Use the [analysis-of-algorithms] tag for the time taken by particular algorithms.)
Type structure is a syntactic discipline for enforcing levels of abstraction.
394 questions
Circuit complexity is the study of resource-bounded circuits and the functions computed by such circuits.
386 questions
Programming languages, in particular, focussing on their semantics.
372 questions
Theoretical questions about Machine learning, especially Computational Learning Theory, including Algorithmic Learning Theory, PAC learning, and Bayesian Inference
Properties and applications of data structures, such as space lower bounds, or time complexity of insertion and deletion of objects.
349 questions
SAT stands for the Boolean satisfiability problem.
questions about lowerbounds on functions, usually the complexity of an algorithm or a problem
279 questions
Computational Geometry is the study of geometric problems from a computational perspective. Examples of problems include: computation of geometric objects such as convex hulls, dimensionality reductio…
269 questions
How hard is counting the number of solutions?
268 questions
Church's formal system used in computatability, programming languages and proof theory to represent effective functions, programs and their computation, and proofs.
265 questions
Theoretical aspects of cryptography and information security.
260 questions
Questions in probability theory
244 questions
The Turing machine is a fundamental model of computation, especially in theoretical work.
233 questions
Linear algebra deals with vector spaces and linear transformations.
227 questions
Questions about Boolean functions and their analysis
217 questions
An algorithm whose behaviour is determined by its input and a generator producing uniformly random numbers.
212 questions
Mathematical and computational method for finding the best outcome in a given mathematical model where the list of requirements is represented as linear relationships.
207 questions
Questions in Information Theory
203 questions
Machine learning and learning theory: PAC learning, algorithmic learning theory, and computational aspects of Bayesian inference and graphical models.
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