On maximizing a monotone k-submodular function subject to a matroid constraint
A k-submodular function is an extension of a submodular function in that its input is given by k disjoint subsets instead of a single subset. For unconstrained nonnegative k-submodular maximization, Ward and Živný proposed a constant-factor approximation algorithm, which was improved by the recent w...
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| Veröffentlicht in: | Discrete optimization Jg. 23; S. 105 - 113 |
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| 1. Verfasser: | |
| Format: | Journal Article |
| Sprache: | Englisch |
| Veröffentlicht: |
Elsevier B.V
01.02.2017
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| Schlagworte: | |
| ISSN: | 1572-5286, 1873-636X |
| Online-Zugang: | Volltext |
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| Zusammenfassung: | A k-submodular function is an extension of a submodular function in that its input is given by k disjoint subsets instead of a single subset. For unconstrained nonnegative k-submodular maximization, Ward and Živný proposed a constant-factor approximation algorithm, which was improved by the recent work of Iwata, Tanigawa and Yoshida presenting a 1/2-approximation algorithm. Iwata et al. also provided a k/(2k−1)-approximation algorithm for nonnegative monotone k-submodular maximization and proved that its approximation ratio is asymptotically tight. More recently, Ohsaka and Yoshida proposed constant-factor algorithms for nonnegative monotone k-submodular maximization with several size constraints. However, while submodular maximization with various constraints has been extensively studied, no approximation algorithm has been developed for constrained k-submodular maximization, except for the case of size constraints.
In this paper, we prove that a greedy algorithm outputs a 1/2-approximate solution for nonnegative monotone k-submodular maximization with a matroid constraint. The algorithm runs in O(M|E|(IO+kEO)) time, where M is the size of a maximal optimal solution, |E| is the size of the ground set, and IO,EO represent the time for the independence oracle of the matroid and the evaluation oracle of the k-submodular function, respectively. |
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| ISSN: | 1572-5286 1873-636X |
| DOI: | 10.1016/j.disopt.2017.01.003 |