ASU 506 All Soviet Union MO 1989 equal altitudes of 2 walkers on mountains
Source:
August 14, 2019
combinatoricsgeometrycombinatorial geometry
Problem Statement
Two walkers are at the same altitude in a range of mountains. The path joining them is piecewise linear with all its vertices above the two walkers. Can they each walk along the path until they have changed places, so that at all times their altitudes are equal?