TY - JOUR
T1 - A linear-time algorithm to find a pair of arc-disjoint spanning in-arborescence and out-arborescence in a directed acyclic graph
AU - Bérczi, Kristóf
AU - Fujishige, Satoru
AU - Kamiyama, Naoyuki
N1 - Funding Information:
1 The present research was partly supported by a Grant-in-Aid from the Ministry of Education, Culture, Sports, Science and Technology of Japan.
PY - 2009/11/15
Y1 - 2009/11/15
N2 - Suppose that we are given a directed graph D = (V, A) with specified vertices r1, r2 ∈ V. In this paper, we consider the problem of discerning the existence of a pair of arc-disjoint spanning in-arborescence rooted at r1 and out-arborescence rooted at r2, and finding such arborescences if they exist. It is known (Bang-Jensen (1991) [1]) that this problem is NP-complete even if r1 = r2. As a special case, it is only known (Bang-Jensen (1991) [1]) that this problem in a tournament can be solved in polynomial time. In this paper, we give a linear-time algorithm for this problem in a directed acyclic graph. We also consider an extension of our problem to the case where we have multiple roots for in-arborescences and out-arborescences, respectively.
AB - Suppose that we are given a directed graph D = (V, A) with specified vertices r1, r2 ∈ V. In this paper, we consider the problem of discerning the existence of a pair of arc-disjoint spanning in-arborescence rooted at r1 and out-arborescence rooted at r2, and finding such arborescences if they exist. It is known (Bang-Jensen (1991) [1]) that this problem is NP-complete even if r1 = r2. As a special case, it is only known (Bang-Jensen (1991) [1]) that this problem in a tournament can be solved in polynomial time. In this paper, we give a linear-time algorithm for this problem in a directed acyclic graph. We also consider an extension of our problem to the case where we have multiple roots for in-arborescences and out-arborescences, respectively.
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U2 - 10.1016/j.ipl.2009.09.004
DO - 10.1016/j.ipl.2009.09.004
M3 - Article
AN - SCOPUS:70350020745
SN - 0020-0190
VL - 109
SP - 1227
EP - 1231
JO - Information Processing Letters
JF - Information Processing Letters
IS - 23-24
ER -