On multipartite tournaments
نویسندگان
چکیده
منابع مشابه
On two-path convexity in multipartite tournaments
In the context of two-path convexity, we study the rank, Helly number, Radon number, Caratheodory number, and hull number for multipartite tournaments. We show the maximum Caratheodory number of a multipartite tournament is 3. We then derive tight upper bounds for rank in both general multipartite tournaments and clone-free multipartite tournaments. We show that these same tight upper bounds ho...
متن کاملStrong subtournaments of multipartite tournaments
An orientation of a complete graph is a tournament, and an orientation of a complete n-partite graph is an n-partite tournament. For each n 2:: 4, there exist examples of strongly connected n-partite tournament without any strongly connected subtournaments of order p 2:: 4. If D is a digraph, then let d+ (x) be the out degree and d(x) the indegree of the vertex x in D. The minimum (maximum) out...
متن کاملk-kernels in multipartite tournaments
Let D be a digraph, V (D) and A(D) will denote the sets of vertices and arcs of D, respectively. A (k, l)-kernel N of D is a k-independent set of vertices (if u, v ∈ N then d(u, v), d(v, u) ≥ k) and l-absorbent (if u ∈ V (D) − N then there exists v ∈ N such that d(u, v) ≤ l). A k-kernel is a (k, k − 1)-kernel. An m-partite tournament is an orientation of an m-partite complete graph. In this pap...
متن کاملConvex invariants in multipartite tournaments
In the study of convexity spaces, the most common convex invariants are based on notions of independence with respect to taking convex hulls. In [D.B. Parker, R.F. Westhoff and M.J. Wolf, Discuss. Math. Graph Theory 29 (2009), 51–69], H-independence, R-independence and convex independence were studied to prove results about the Helly number, Radon number and rank of a clone-free multipartite to...
متن کاملWeakly Hamiltonian-connected ordinary multipartite tournaments
We characterize weakly Hamiltonian-connected ordinary multipartite tournaments. Our result generalizes such a characterization for tournaments by Thomassen and implies a polynomial algorithm to decide the existence of a Hamiltonian path connecting two given vertices in an ordinary multipartite tournament and find one, if it exists.
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ژورنال
عنوان ژورنال: Journal of Combinatorial Theory, Series B
سال: 1991
ISSN: 0095-8956
DOI: 10.1016/0095-8956(91)90069-v