MEMO 2017 ekipno problem 3
Dodao/la: arhiva12. rujna 2018.
There is a lamp on each cell of a board. Each lamp is either on or off. A lamp is called bad if it has an even number of neighbours that are on. What is the smallest possible number of bad lamps on such a board?
(Two lamps are neighbours if their respective cells share a side.)
Izvor: Srednjoeuropska matematička olimpijada 2017, ekipno natjecanje, problem 3