In
computer science
Computer science is the study of computation, information, and automation. Computer science spans Theoretical computer science, theoretical disciplines (such as algorithms, theory of computation, and information theory) to Applied science, ...
and
operations research
Operations research () (U.S. Air Force Specialty Code: Operations Analysis), often shortened to the initialism OR, is a branch of applied mathematics that deals with the development and application of analytical methods to improve management and ...
, exact algorithms are
algorithm
In mathematics and computer science, an algorithm () is a finite sequence of Rigour#Mathematics, mathematically rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algo ...
s that always solve an optimization problem to optimality.
Unless
P = NP, an exact algorithm for an
NP-hard optimization problem cannot run in worst-case
polynomial time. There has been extensive research on finding exact algorithms whose running time is exponential with a low base.
See also
*
Approximation-preserving reduction
*
APX is the class of problems with some constant-factor approximation algorithm
*
Heuristic algorithm
*
PTAS - a type of approximation algorithm that takes the approximation ratio as a parameter
References
{{reflist
Computational complexity theory
Optimization algorithms and methods