Abstract. Rotation distance quantifies the difference in shape between two rooted binary trees of the same size by counting the minimum number of elementary changes needed to tra...
We consider the problem of packing two-dimensional rectangles into the minimum number of unit squares, when 90 rotations are allowed. Our main contribution is a polynomial-time al...
We study the problem of uniformly partitioning the edge set of a tree with n edges into k connected components, where k ≤ n. The objective is to minimize the ratio of the maximu...
Bang Ye Wu, Hung-Lung Wang, Shih Ta Kuan, Kun-Mao ...
We study the following two functions: d(n, c) and d(n, c); d(n, c) (d(n, c)) is the minimum number k such that every c-edge-colored undirected (directed) graph of order n and mini...
In this paper, a multi-period assignment problem is studied that arises as part of a weekly planning problem at mail processing and distribution centers. These facilities contain ...
For an oriented graph G with n vertices, let f(G) denote the minimum number of transitive subtournaments that decompose G. We prove several results on f(G). In particular, if G is...
Let G be a graph. A vertex labeling of G is distinguishing if the only label-preserving automorphism of G is the identity map. The distinguishing number of G, D(G), is the minimum...
A homomorphism from an oriented graph G to an oriented graph H is a mapping from the set of vertices of G to the set of vertices of H such that -----(u)(v) is an arc in H whenever...
We prove that the minimum number of distinct hamiltonian paths in a strong tournament of order n is 5 n-1 3 . A known construction shows this number is best possible when n 1 mod...