MathDB
game with numbers 1, ... ,mn in a mxn board

Source: 1996 Estonia National Olympiad Final Round grade 9

March 11, 2020
tablecombinatoricsboard

Problem Statement

Three children wanted to make a table-game. For that purpose they wished to enumerate the mnmn squares of an m×nm \times n game-board by the numbers 1,...,mn1, ... ,mn in such way that the numbers 11 and mnmn lie in the corners of the board and the squares with successive numbers have a common edge. The children agreed to place the initial square (with number 11) in one of the corners but each child wanted to have the final square (with number mnmn ) in different corner. For which numbers mm and nn is it possible to satisfy the wish of any of the children?