No two cycles share an edge
Source: ICMC 2023 Round 1 P4
November 28, 2022
college contestscombinatoricsgraph theoryICMC
Problem Statement
Let be a simple graph with vertices and edges such that no two cycles share an edge. Prove that .Note: A simple graph is a graph with at most one edge between any two vertices and no edges from any vertex to itself. A cycle is a sequence of distinct vertices such that there is an edge between any two consecutive vertices, and between and .Proposed by Ethan Tan