TY - GEN

T1 - (In)approximability results for pattern matching problems

AU - Clifford, Raphaël

AU - Popa, Alexandru

PY - 2010/12/1

Y1 - 2010/12/1

N2 - We consider the approximability of three recently introduced pattern matching problems which have been shown to be NP-hard. Given two strings as input, the first problem is to find the longest common parameterised subsequence between two strings. The second is a maximisation variant of generalised function matching and the third is a a maximisation variant of generalised parameterised matching. We show that in all three cases there exists an ∈ > 0 such that there is no polynomial time (1 - ∈)-approximation algorithm, unless P = NP. We then present a polynomial time √ 1/OPT-approximation algorithm for a variant of generalised parameterised matching for which no previous approximation results are known.

AB - We consider the approximability of three recently introduced pattern matching problems which have been shown to be NP-hard. Given two strings as input, the first problem is to find the longest common parameterised subsequence between two strings. The second is a maximisation variant of generalised function matching and the third is a a maximisation variant of generalised parameterised matching. We show that in all three cases there exists an ∈ > 0 such that there is no polynomial time (1 - ∈)-approximation algorithm, unless P = NP. We then present a polynomial time √ 1/OPT-approximation algorithm for a variant of generalised parameterised matching for which no previous approximation results are known.

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M3 - Conference contribution

AN - SCOPUS:84869143041

SN - 9788001045978

T3 - Proceedings of the Prague Stringology Conference 2010

SP - 52

EP - 62

BT - Proceedings of the Prague Stringology Conference 2010

T2 - Prague Stringology Conference 2010, PSC 2010

Y2 - 30 August 2010 through 1 September 2010

ER -