MathDB
Weird weighted graph

Source: St Petersburg 2022 10.7 (rephrased)

September 28, 2022
combinatoricsgraph theoryalgebraKvant

Problem Statement

Given is a graph GG of n+1n+1 vertices, which is constructed as follows: initially there is only one vertex vv, and one a move we can add a vertex and connect it to exactly one among the previous vertices. The vertices have non-negative real weights such that vv has weight 00 and each other vertex has a weight not exceeding the avarage weight of its neighbors, increased by 11. Prove that no weight can exceed n2n^2.