Peer-reviewedCC BY 4.0The Electronic Journal of Combinatorics
On the Minimum Number of Hamilton Cycles in Hamiltonian Threshold Graphs: A Simple Proof
Abstract
A graph is called a threshold graph if it is induced-{P4,C4,2K2} free. In 2020, Qiao and Zhan [J. Graph Theory 93 (2020) 222--229] determined the minimum number of Hamilton cycles in a Hamiltonian threshold graph and characterized the extremal graphs attaining this minimum. We show that every Hamiltonian threshold graph contains a special spanning subgraph, from which their two results follow directly.
Related
BibTeX
@article{li2026minimum,
title = {{On the Minimum Number of Hamilton Cycles in Hamiltonian Threshold Graphs: A Simple Proof}},
author = {Chengli Li and Feng Liu},
journal = {The Electronic Journal of Combinatorics},
year = {2026},
month = oct,
doi = {10.37236/15076},
url = {https://www.combinatorics.org/ojs/index.php/eljc/article/view/v33i4p25},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - On the Minimum Number of Hamilton Cycles in Hamiltonian Threshold Graphs: A Simple Proof
AU - Chengli Li
AU - Feng Liu
PY - 2026
DA - 2026/10/23
JO - The Electronic Journal of Combinatorics
DO - 10.37236/15076
UR - https://www.combinatorics.org/ojs/index.php/eljc/article/view/v33i4p25
AB - A graph is called a threshold graph if it is induced-{P_4,C_4,2K_2} free. In 2020, Qiao and Zhan [J. Graph Theory 93 (2020) 222--229] determined the minimum number of Hamilton cycles in a Hamiltonian threshold graph and characterized the extremal graphs attaining this minimum. We show that every Hamiltonian threshold graph contains a special spanning subgraph, from which their two results follow directly.
SN - 1077-8926
ER -