Parameterized algorithms for the Steiner arborescence problem on a hypercube
Motivated by a phylogeny reconstruction problem in evolutionary biology, we study the minimum Steiner arborescence problem on directed hypercubes (MSA-DH). Given m, representing the directed hypercube Q→m, and a set of terminals R, the problem asks to find a Steiner arborescence that spans R with mi...
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| Published in: | Acta informatica Vol. 62; no. 1; p. 6 |
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| Main Authors: | , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
Heidelberg
Springer Nature B.V
01.03.2025
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| Subjects: | |
| ISSN: | 0001-5903, 1432-0525 |
| Online Access: | Get full text |
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| Summary: | Motivated by a phylogeny reconstruction problem in evolutionary biology, we study the minimum Steiner arborescence problem on directed hypercubes (MSA-DH). Given m, representing the directed hypercube Q→m, and a set of terminals R, the problem asks to find a Steiner arborescence that spans R with minimum cost. As m implicitly represents Q→m comprising 2m vertices, the running time analyses of traditional Steiner tree algorithms on general graphs does not give a clear understanding of the actual complexity of this problem. We present algorithms that exploit the structure of the hypercube and run in FPT time. We explore the MSA-DH problem on three natural parameters—|R|, and two above-guarantee parameters, number of Steiner nodes p and penalty q (defined as the extra cost above m incurred by the solution). For above-guarantee parameters, the parameterized MSA-DH problem take p≥0 or q≥0 as input, and outputs a Steiner arborescence with at most |R|+p-1 or m+q edges respectively. We present the following results (O~ hides the polynomial factors): An exact algorithm that runs in O~(3|R|) time.A randomized algorithm that runs in O~(9q) time with success probability ≥4-q.An exact algorithm that runs in O~(36q) time.A (1+q)-approximation algorithm that runs in O~(1.25284q) time.An Opℓmax-additive approximation algorithm that runs in O~(ℓmaxp+2) time, where ℓmax is the maximum distance of any terminal from the root. |
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| Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 14 |
| ISSN: | 0001-5903 1432-0525 |
| DOI: | 10.1007/s00236-024-00474-8 |