numbering k from n lines in general position
Source: Mathematics Regional Olympiad of Mexico Center Zone 2018 P3
November 13, 2021
combinatorial geometrycombinatorics
Problem Statement
Consider lines in the plane in general position, that is, there are not three of the lines that pass through the same point. Determine if it is possible to label the points where these lines are inserted with the numbers through (using each number exactly once), so that on each line, the labels of the points of that line are arranged in increasing order (in one of the two directions in which they can be traversed).