MathDB
Remains a forest

Source: STEMS 2021 CS Cat B Q2

January 23, 2021
combinatoricsgraph theory

Problem Statement

Given two forests AA and BB with V(A)=V(B)V(A) = V(B), that is the graphs are over same vertex set. Suppose AA has strictly more edges than BB. Prove that there exists an edge of AA which if included in the edge set of BB, then BB will still remain a forest. Graphs are undirected