The paper presents results related to a theorem of Szigeti on covering symmetric skew-supermodular set functions by hypergraphs. We prove the following generalization using a variation of Schrijver’s… (More)

Given a digraph D = (V,A) and a positive integer k, an arc set F ⊆ A is called a k-arborescence if it is the disjoint union of k spanning arborescences. The problem of nding a minimum cost… (More)

The problem of covering minimum cost common bases of two matroids is NPcomplete, even if the two matroids coincide, and the costs are all equal to 1. In this paper we show that the following special… (More)

A new approach to undirected splitting-off is presented in this paper. We study the behaviour of splitting-off algorithms when applied to the problem of covering a symmetric skew-supermodular set… (More)

A cycle C ⊆ E in a graph G = (V,E) is nonseparating if G−C is connected (note that we only delete the edges of the cycle). We study the algorithmic problem of deciding whether a graph contains a… (More)

Motivated by a conjecture of Liang [Y.-C. Liang. Anti-magic labeling of graphs. PhD thesis, National Sun Yat-sen University, 2013.], we introduce a restricted path packing problem in bipartite graphs… (More)