Apples on a tree
Source: 2023 Israel Olympic Revenge P1
June 15, 2023
olympic revengecombinatoricsgraph theory
Problem Statement
Armadillo and Badger are playing a game. Armadillo chooses a nonempty tree (a simple acyclic graph) and places apples at some of its vertices (there may be several apples on a single vertex). First, Badger picks a vertex and eats all its apples. Next, Armadillo and Badger take turns alternatingly, with Armadillo starting. On the -th turn the animal whose turn it is picks a vertex adjacent to that hasn't been picked before and eats all its apples. The game ends when there is no such vertex .Armadillo's goal is to have eaten more apples than Badger once the game ends. Can she fulfill her wish?