There exists a polygonal line
Source:
August 29, 2010
combinatoricscombinatorial geometrygraph theoryExtremal combinatoricsExtremal Graph TheoryIMO Shortlist
Problem Statement
Let be a set of points in the space. From the family of all segments with endpoints in , segments have been selected and colored yellow. Suppose that all yellow segments are of different length. Prove that there exists a polygonal line composed of yellow segments, where , arranged in order of increasing length.