Consider Vertex v, a child of t, with children ui, i from 1 to
n Vertex v, a child of t, with children ui, i from 1 to n P(v) = p
P(v) = p Each child is a subtree that requires ki machines to clean
Each child is a subtree that requires ki machines to clean We order
ui so ki are in decreasing order, without loss of generality We
order ui so ki are in decreasing order, without loss of
generality
Slide 4
Lemma 1 When cleaning subtrees ui from i = 1 to n, number of
machines needed is K, such that k1