MathDB
Labeling marbles that are connected by ropes

Source: Turkey TST 2019 Day 2 P6

March 26, 2019
combinatoricsgraph theory

Problem Statement

kk is a positive integer, Rn=k,(k1),...,1,1,...,k1,kR_{n}={-k, -(k-1),..., -1, 1,..., k-1, k} for n=2kn=2k Rn=k,(k1),...,1,0,1,...,k1,kR_{n}={-k, -(k-1),..., -1, 0, 1,..., k-1, k} for n=2k+1n=2k+1. A mechanism consists of some marbles and white/red ropes that connects some marble pairs. If each one of the marbles are written on some numbers from RnR_{n} with the property that any two connected marbles have different numbers on them, we call it nice labeling. If each one of the marbles are written on some numbers from RnR_{n} with the properties that any two connected marbles with a white rope have different numbers on them and any two connected marbles with a red rope have two numbers with sum not equal to 00, we call it precise labeling. n3n\geq{3}, if every mechanism that is labeled nicely with RnR_{n}, could be labeled precisely with RmR_{m}, what is the minimal value of mm?