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The γ-connected assignment problem
Given a graph and costs of assigning to each vertex one of k different colors, we want to find a minimum cost assignment such that no color q induces a subgraph with more than a given number ( γ q ) of connected components. This problem arose in the context of contiguity-constrained clustering, but...
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Published in: | European journal of operational research 1999-10, Vol.118 (1), p.127-138 |
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Main Authors: | , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | Given a graph and costs of assigning to each vertex one of
k different colors, we want to find a minimum cost assignment such that no color
q induces a subgraph with more than a given number (
γ
q
) of connected components. This problem arose in the context of contiguity-constrained clustering, but also has a number of other possible applications. We show the problem to be NP-hard. Nevertheless, we derive a dynamic programming algorithm that proves the case where the underlying graph is a tree to be solvable in polynomial time. Next, we propose mixed-integer programming formulations for this problem that lead to branch-and-cut and branch-and-price algorithms. Finally, we introduce a new class of valid inequalities to obtain an enhanced branch-and-cut. Extensive computational experiments are reported. |
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ISSN: | 0377-2217 1872-6860 |
DOI: | 10.1016/S0377-2217(98)00305-1 |