Edge-Packing in Planar Graphs

Heath, Lenwood S. and Vergara, John Paul C. (1995) Edge-Packing in Planar Graphs. Technical Report ncstrl.vatech_cs//TR-95-18, Computer Science, Virginia Polytechnic Institute and State University.

Abstract

Maximum G Edge-Packing (EPack-sub G) is the problem of finding the maximum number of edge-disjoint isomorphic copies of a fixed guest graph G in a host graph H. This paper investigates the computational complexity of edge-packing for planar guests and planar hosts. Edge-packing is solvable in polynomial time when both G and H are either a 3-cycle or a k-star (graphs isomorphic to K(sub 1,k). Edge-packing is NP-complete when H is planar and G is either a cycle or a tree with greater than or equal to 3 edges. A strategy for developing polynomial-time approximation algorithms for planar hosts is exemplified by a linear-time approximation algorithm that finds a k-star edge-packing of size at least 1/2 optimal.