Abstract
On-line chain partitioning problem of on-line posets has been open for the past 20 years. The best known on-line algorithm uses \(\frac{5^w-1}{4}\) chains to cover poset of width w. Felsner (Theor. Comput. Sci., 175(2):283–292, 1997) introduced a variant of this problem considering only up-growing posets, i.e. on-line posets in which each new point is maximal at the moment of its arrival. He presented an algorithm using \({\left( {\begin{array}{*{20}c} {{w + 1}} \\ {2} \\ \end{array} } \right)}\) chains for width w posets and proved that his solution is optimal. In this paper, we study on-line chain partitioning of up-growing interval orders. We prove lower bound and upper bound to be 2w−1 for width w posets.
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Piotr Micek and Bartłomiej Bosek are scholars of the project which is co-financed from the European Social Fund and national budget in the frame of The Integrated Regional Operational Programme.
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Baier, P., Bosek, B. & Micek, P. On-line Chain Partitioning of Up-growing Interval Orders. Order 24, 1–13 (2007). https://doi.org/10.1007/s11083-006-9050-0
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DOI: https://doi.org/10.1007/s11083-006-9050-0