论文标题
组合圣诞老人问题或:如何在不均匀的超图中找到良好的匹配
The Combinatorial Santa Claus Problem or: How to Find Good Matchings in Non-Uniform Hypergraphs
论文作者
论文摘要
我们考虑在顶点上的超图$ p \ cup r $,其中每个hypereedge恰好包含一个顶点$ p $。我们的目标是选择一个覆盖所有$ p $的匹配,但是我们允许每个选定的HyperEdge放下除$(1/α)$的所有与$ r $相交的部分(从而放松匹配的约束)。在这里$α$要最小化。我们将这个问题评为组合圣诞老人问题,因为我们在本文中表明,这个问题和圣诞老人问题在其近似性方面几乎相当于。 非平凡的观察结果是,任何均匀的常规超毛图都承认,以$α= O(1)$的轻松匹配是获得圣诞老人问题的特殊情况的恒定近似率的主要步骤,这在文献中引起了极大的关注。自然要问是否可以省略统一条件。我们的主要结果是,当所有超补品都足够大(必要的条件)时,每个(\ log \ log \ log(| r |))$(\ log \ log \ log(| r |))$的每个(不均匀)常规超图都以$α= o(\ log \ log \ log \ log(| r |))的身份承认轻松的匹配。特别是,这意味着一个$ o(\ log \ log \ log(| r |))$ - 组合圣诞老人的近似算法,带有大型Hyperedges。
We consider hypergraphs on vertices $P\cup R$ where each hyperedge contains exactly one vertex in $P$. Our goal is to select a matching that covers all of $P$, but we allow each selected hyperedge to drop all but an $(1/α)$-fraction of its intersection with $R$ (thus relaxing the matching constraint). Here $α$ is to be minimized. We dub this problem the Combinatorial Santa Claus problem, since we show in this paper that this problem and the Santa Claus problem are almost equivalent in terms of their approximability. The non-trivial observation that any uniform regular hypergraph admits a relaxed matching for $α= O(1)$ was a major step in obtaining a constant approximation rate for a special case of the Santa Claus problem, which received great attention in literature. It is natural to ask if the uniformity condition can be omitted. Our main result is that every (non-uniform) regular hypergraph admits a relaxed matching for $α= O(\log\log(|R|))$, when all hyperedges are sufficiently large (a condition that is necessary). In particular, this implies an $O(\log\log(|R|))$-approximation algorithm for the Combinatorial Santa Claus problem with large hyperedges.