MathDB
n points, 2 segments with a common endpoint are of different colors, min colours

Source: Polish second round 1997 p3

January 19, 2020
combinatoricscombinatorial geometryColoringsegments

Problem Statement

Let be given nn points, no three of which are on a line. All the segments with endpoints in these points are colored so that two segments with a common endpoint are of different colors. Determine the least number of colors for which this is possible