Abstract

A triangle-free graph is maximal if the addition of any edge creates a triangle. For n ⩾ 5, we show there is an n-node m-edge maximal triangle-free graph if and only if it is complete bipartite or 2 n − 5 ⩽ m ⩽⌊( n − 1) 2/4⌋ + 1. A diameter 2 graph is minimal if the deletion of any edge increases the diameter. We show that a triangle-free graph is maximal if and only if it is minimal of diameter 2. For n > n o where n o is a vastly huge number, Füredi showed that an n-node nonbipartite minimal diameter 2 graph has at most ⌊( n − 1) 2/4⌋ + 1 edges. We demonstrate that n 0 ⩾ 6 by producing a 6-node nonbipartite minimal diameter 2 graph with 8 edges.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.