{"title":"On queens and tours","authors":"Pieter Jacobs, Andrés López Martínez, Frits Spieksma","doi":"10.1016/j.orl.2025.107283","DOIUrl":null,"url":null,"abstract":"<div><div>Given the complete graph on <em>n</em> vertices, where <span><math><mi>n</mi><mo>≥</mo><mn>3</mn></math></span>, we define two Hamiltonian cycles as <em>cyclic disjoint</em> if, for each pair of vertices, the distance between them in one Hamiltonian cycle differs from the distance between them in the other Hamiltonian cycle. We investigate the number of pairwise cyclic disjoint tours that exist in <span><math><msub><mrow><mi>K</mi></mrow><mrow><mi>n</mi></mrow></msub></math></span>. Specifically, we identify when pairs of cyclic disjoint tours can occur and provide a procedure to generate <span><math><mfrac><mrow><mi>m</mi><mo>−</mo><mn>1</mn></mrow><mrow><mn>2</mn></mrow></mfrac></math></span> pairwise cyclic disjoint tours, where <em>m</em> is the smallest prime factor of <em>n</em>. Finally, we demonstrate that the number <span><math><mfrac><mrow><mi>m</mi><mo>−</mo><mn>1</mn></mrow><mrow><mn>2</mn></mrow></mfrac></math></span> of pairwise cyclic disjoint tours is maximized when <em>n</em> is prime.</div></div>","PeriodicalId":54682,"journal":{"name":"Operations Research Letters","volume":"61 ","pages":"Article 107283"},"PeriodicalIF":0.8000,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Operations Research Letters","FirstCategoryId":"91","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0167637725000446","RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"OPERATIONS RESEARCH & MANAGEMENT SCIENCE","Score":null,"Total":0}
引用次数: 0
Abstract
Given the complete graph on n vertices, where , we define two Hamiltonian cycles as cyclic disjoint if, for each pair of vertices, the distance between them in one Hamiltonian cycle differs from the distance between them in the other Hamiltonian cycle. We investigate the number of pairwise cyclic disjoint tours that exist in . Specifically, we identify when pairs of cyclic disjoint tours can occur and provide a procedure to generate pairwise cyclic disjoint tours, where m is the smallest prime factor of n. Finally, we demonstrate that the number of pairwise cyclic disjoint tours is maximized when n is prime.
期刊介绍:
Operations Research Letters is committed to the rapid review and fast publication of short articles on all aspects of operations research and analytics. Apart from a limitation to eight journal pages, quality, originality, relevance and clarity are the only criteria for selecting the papers to be published. ORL covers the broad field of optimization, stochastic models and game theory. Specific areas of interest include networks, routing, location, queueing, scheduling, inventory, reliability, and financial engineering. We wish to explore interfaces with other fields such as life sciences and health care, artificial intelligence and machine learning, energy distribution, and computational social sciences and humanities. Our traditional strength is in methodology, including theory, modelling, algorithms and computational studies. We also welcome novel applications and concise literature reviews.