Gap for Max-Internal BFS and DFS trees

Determine estimates for the gap between the maximum number of internal vertices in Breadth-First Search or Depth-First Search trees and the optimum of the Maximum Internal Spanning Tree problem.

Background

The paper compares Max-Internal search-tree problems with the unrestricted Maximum Internal Spanning Tree problem. Although the general comparison establishes that search-tree solutions yield lower bounds for the spanning-tree optimum, the authors identify the specific quantitative relationship for Breadth-First Search and Depth-First Search as unresolved.