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arXiv 2102.05747cs.CGcs.DS
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左下锚定矩形填充的一个较好下界

A better lower bound for Lower-Left Anchored Rectangle Packing

Ruben Hoeksma, Matthew Maat

摘要:

给定包含原点的单位正方形中的任意一组点$S$,是否存在一组轴对齐的矩形,$S$中的每个点对应一个矩形,使得每个矩形的左下角都有$S$中的一个点,它们两两内部不相交,并且它们覆盖的总面积至少为1/2?这个问题也被称为弗里德曼猜想(证明这样一组矩形确实存在),自1969年艾伦·弗里德曼提出以来一直是开放的。在本文中,我们提高了最好的已知下限的总面积,可以覆盖从0.09121到0.1039。虽然这一步很小,但我们引入了新的见解,推动了这种分析的极限。我们的下界使用了一个贪心算法,在$S$中的点有一个特定的顺序。因此,这也意味着该贪心算法实现了0.1039的近似比。我们补充的结果与一个自然类的贪心算法,其中包括一个达到下限的近似比的上限为3/4。

英文摘要:

Given any set of points $S$ in the unit square that contains the origin, does a set of axis aligned rectangles, one for each point in $S$, exist, such that each of them has a point in $S$ as its lower-left corner, they are pairwise interior disjoint, and the total area that they cover is at least 1/2? This question is also known as Freedman's conjecture (conjecturing that such a set of rectangles does exist) and has been open since Allen Freedman posed it in 1969. In this paper, we improve the best known lower bound on the total area that can be covered from 0.09121 to 0.1039. Although this step is small, we introduce new insights that push the limits of this analysis. Our lower bound uses a greedy algorithm with a particular order of the points in $S$. Therefore, it also implies that this greedy algorithm achieves an approximation ratio of 0.1039. We complement the result with an upper bound of 3/4 on the approximation ratio for a natural class of greedy algorithms that includes the one that achieves the lower bound.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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