Find a way to assign natural numbers - ISL 1971
Source:
September 22, 2010
combinatoricsGraph coloringconstructionIMO Shortlist
Problem Statement
Let be a natural number. Find a way to assign natural numbers to the vertices of a regular -gon such that the following conditions are satisfied:(1) only digits and are used;(2) each number consists of exactly digits;(3) different numbers are assigned to different vertices;(4) the numbers assigned to two neighboring vertices differ at exactly one digit.