With what Frequency are Apparently Intractable Problems Difficult?

An algorithm is almost polynomial-time (apt) iff there is a polynomial p such that for all n, the algorithm halts within p(n) steps on all by at most p(n) inputs of size at most n. It is nown that for NP-complete and polynomial space-complete problems, as well as certain other apparently intractable...

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Bibliographic Details
Main Authors: Meyer, A.R., Paterson, M.S.
Published: 2023
Online Access:https://hdl.handle.net/1721.1/148954
Description
Summary:An algorithm is almost polynomial-time (apt) iff there is a polynomial p such that for all n, the algorithm halts within p(n) steps on all by at most p(n) inputs of size at most n. It is nown that for NP-complete and polynomial space-complete problems, as well as certain other apparently intractable problems such as integer factoring, the following conditions are equivalent: (1) the problem is solveable by an apt algorithm, (2) the problem (or its complement) is polynomial-time transformable to a polynomial-sparse set, (3) the problem is solvable in polynomial time.