,
Samir Khuller
,
Emilie Rivkin
Creative Commons Attribution 4.0 International license
We study generalizations of the classical Vertex Cover and Edge Cover problems that incorporate group-wise coverage. Our first focus is the Capacitated Partition Vertex Cover (C-PVC) problem in hypergraphs. In C-PVC, we are given a hypergraph with capacities on its vertices and a partition of the hyperedge set into ω distinct groups. The objective is to select a minimum size subset of vertices that satisfies two main conditions: (1) in each group, the total number of covered hyperedges meets a specified threshold, and (2) the number of hyperedges assigned to any vertex respects its capacity constraint. A covered hyperedge is required to be assigned to a selected vertex that belongs to the hyperedge. This formulation generalizes classical Vertex Cover, Partial Vertex Cover, and Partition Vertex Cover. We investigate two primary variants: soft capacitated (multiple copies of a vertex are allowed) and hard capacitated (each vertex can be chosen at most once). Let f denote the rank of the hypergraph (i.e., the maximum number of vertices contained in any single hyperedge). Our main contributions are: (i) an (f+1)-approximation algorithm for the weighted soft-capacitated C-PVC problem, which runs in n^O(ω) time, and (ii) an (f+ε)-approximation algorithm for the unweighted hard-capacitated C-PVC problem, which runs in n^O(ω/ε) time. We also study a natural generalization of the edge cover problem, the Weighted Partition Edge Cover (W-PEC) problem, where each edge has an associated weight, and the vertex set is partitioned into groups. For each group, the goal is to cover at least a specified number of vertices using incident edges, while minimizing the total weight of the selected edges. We present the first exact polynomial-time algorithm for the weighted case, improving runtime from O(ω n³) to O(mn + n²log n) and simplifying the algorithmic structure over prior unweighted approaches (that rely on the tropical matching problem).
@InProceedings{dabas_et_al:LIPIcs.APPROX/RANDOM.2026.8,
author = {Dabas, Rajni and Khuller, Samir and Rivkin, Emilie},
title = {{Capacitated Partition Vertex Cover and Partition Edge Cover}},
booktitle = {Approximation, Randomization, and Combinatorial Optimization. Algorithms and Techniques (APPROX/RANDOM 2026)},
pages = {8:1--8:24},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-449-9},
ISSN = {1868-8969},
year = {2026},
volume = {392},
editor = {Singh, Mohit and Gur, Tom},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.APPROX/RANDOM.2026.8},
URN = {urn:nbn:de:0030-drops-277257},
doi = {10.4230/LIPIcs.APPROX/RANDOM.2026.8},
annote = {Keywords: Approximation algorithms, capacitated vertex cover, iterative rounding}
}