Out-branchings with extremal number of leaves
Jørgen Bang‐Jensen, Gregory Gutin · University of Southern Denmark Research Portal (University of Southern Denmark) · 2010
A subdigraph T of a digraph D is called an out-tree if T is an oriented tree with just one vertex s of in-degree zero. A spanning outtree is called an out-branching. A vertex x of an out-branching B is called a leaf if d + B (x) = 0. This is mainly a survey paper on out-branchings with minimum and maximum number of leaves. We give short proofs of some well-known theorems. 1