MathDB

7

Part of 1987 ITAMO

Problems(1)

largest possible total length of the walls, on a mza of n^2 unit square cells

Source: ITAMO 1987 p7

2/2/2020
A square paper of side nn is divided into n2n^2 unit square cells. A maze is drawn on the paper with unit walls between some cells in such a way that one can reach every cell from every other cell not crossing any wall. Find, in terms of nn, the largest possible total length of the walls.
combinatorics