摘要

An edge ordering of a graph G is an injection f : E -%26gt; R, the set of real numbers. A path in G for which the edge ordering f increases along its edge sequence is called an f-ascent; an f-ascent is maximal if it is not contained in a longer f-ascent. The depression of G is the smallest integer k such that any edge ordering f has a maximal f-ascent of length at most k. We characterize the class of graphs with depression three and without adjacent vertices of degree three or higher.

  • 出版日期2013-6-6