2012 年 E95.D 巻 3 号 p. 769-777
The k-edge-connectivity augmentation problem with bipartition constraints (kECABP, for short) is defined by “Given an undirected graph G=(V,E) and a bipartition π={VB,VW} of V with VB∩VW=∅, find an edge set Ef of minimum cardinality, consisting of edges that connect VB and VW, such that G'=(V,E∪Ef) is k-edge-connected.” The problem has applications for security of statistical data stored in a cross tabulated table, and so on. In this paper we propose a fast algorithm for finding an optimal solution to (σ+1)ECABP in O(|V||E|+|V2|log |V|) time when G is σ-edge-connected (σ > 0), and show that the problem can be solved in linear time if σ ∈ {1,2}.