Crossing ٍٍChords
Source: Iranian Combinatorics Olympiad 2020 P3
April 24, 2020
combinatorics
Problem Statement
points and some chords between them is given.
In every step we can take two chords with a common point other than and erase exactly one of and draw let be the minimum of chords after some steps. Find the maximum of over all initial positions.
In every step we can take two chords with a common point other than and erase both of and draw let be the minimum of chords after some steps. Find the maximum of over all initial positions.Proposed by Afrouz Jabalameli, Abolfazl Asadi