{"id":552,"global_id":"sites.cs.queensu.ca\/ocw2026?id=552","global_id_lineage":["sites.cs.queensu.ca\/ocw2026?id=552"],"author":"2","status":"publish","date":"2026-05-04 18:59:20","date_utc":"2026-05-04 18:59:20","modified":"2026-05-04 18:59:20","modified_utc":"2026-05-04 18:59:20","url":"https:\/\/sites.cs.queensu.ca\/ocw2026\/event\/a-report-on-the-results-of-the-ongoing-investigation-of-the-weak-closure-algorithm-wca\/","rest_url":"https:\/\/sites.cs.queensu.ca\/ocw2026\/wp-json\/tribe\/events\/v1\/events\/552","title":"A report on the results of the ongoing investigation of the Weak Closure Algorithm (WCA)","description":"<p><strong>Adrian Lee, University of Guelph<\/strong><\/p>\n<p>The non-Hamiltonian cycle decision problem is co-NP complete for which the existence of a polynomial time algorithm is unknown. In 2017, Gismondi and Lee developed a heuristic algorithm (O(n8)) called the weak closure algorithm (WCA) that investigated this problem using a total of 461 snarks that are known to be non-Hamiltonian. This algorithm successfully decided these snarks to be non-Hamiltonian. In this presentation, a follow up report of an ongoing investigation of the WCA testing a total of 459,986 3-regular graphs with vertex counts ranging from 4 to 18; and also 153,000 out of 510,489 3-regular graphs with 20 vertices is presented. All non-Hamiltonian graphs were verified non-Hamiltonian, and, no Hamiltonian graph was decided non-Hamiltonian (Hamiltonian graphs cause the WCA to exit Undecided) via Maple 2023. All tested graphs were generated by GENREG, an open-source software developed by Meringer in 1999.<\/p>","excerpt":"","slug":"a-report-on-the-results-of-the-ongoing-investigation-of-the-weak-closure-algorithm-wca","image":false,"all_day":false,"start_date":"2026-05-09 14:00:00","start_date_details":{"year":"2026","month":"05","day":"09","hour":"14","minutes":"00","seconds":"00"},"end_date":"2026-05-09 14:30:00","end_date_details":{"year":"2026","month":"05","day":"09","hour":"14","minutes":"30","seconds":"00"},"utc_start_date":"2026-05-09 14:00:00","utc_start_date_details":{"year":"2026","month":"05","day":"09","hour":"14","minutes":"00","seconds":"00"},"utc_end_date":"2026-05-09 14:30:00","utc_end_date_details":{"year":"2026","month":"05","day":"09","hour":"14","minutes":"30","seconds":"00"},"timezone":"UTC+0","timezone_abbr":"UTC+0","cost":"","cost_details":{"currency_symbol":"$","currency_code":"USD","currency_position":"prefix","values":[]},"website":"","show_map":true,"show_map_link":true,"hide_from_listings":false,"sticky":false,"featured":false,"categories":[{"name":"Contributed Talk","slug":"contributed-talk","term_group":0,"term_taxonomy_id":4,"taxonomy":"tribe_events_cat","description":"","parent":0,"count":16,"filter":"raw","id":4,"urls":{"self":"https:\/\/sites.cs.queensu.ca\/ocw2026\/wp-json\/tribe\/events\/v1\/categories\/4","collection":"https:\/\/sites.cs.queensu.ca\/ocw2026\/wp-json\/tribe\/events\/v1\/categories"}}],"tags":[],"venue":{"id":337,"author":"2","status":"publish","date":"2026-05-01 19:14:08","date_utc":"2026-05-01 19:14:08","modified":"2026-05-01 20:08:00","modified_utc":"2026-05-01 20:08:00","url":"https:\/\/sites.cs.queensu.ca\/ocw2026\/venue\/walter-light-hall-210\/","venue":"WLH 210","description":"<p>Please refer to the <a href=\"https:\/\/sites.cs.queensu.ca\/ocw2026\/accessibility\/\">Accessibility<\/a> page for classroom amenities.<\/p>","slug":"walter-light-hall-210","address":"Walter Light Hall, 19 Union St.","city":"Kingston","country":"Canada","province":"ON","zip":"K7L 3N9","website":"https:\/\/www.queensu.ca\/classrooms\/node\/37#WALGHT-210","stateprovince":"ON","json_ld":{"@type":"Place","name":"WLH 210","description":"&lt;p&gt;Please refer to the Accessibility page for classroom amenities.&lt;\/p&gt;\\n","url":"","address":{"@type":"PostalAddress","streetAddress":"Walter Light Hall, 19 Union St.","addressLocality":"Kingston","addressRegion":"ON","postalCode":"K7L 3N9","addressCountry":"Canada"},"telephone":"","sameAs":"https:\/\/www.queensu.ca\/classrooms\/node\/37#WALGHT-210"},"show_map":true,"show_map_link":true,"global_id":"sites.cs.queensu.ca\/ocw2026?id=337","global_id_lineage":["sites.cs.queensu.ca\/ocw2026?id=337"]},"organizer":[],"custom_fields":[],"json_ld":{"@context":"http:\/\/schema.org","@type":"Event","name":"A report on the results of the ongoing investigation of the Weak Closure Algorithm (WCA)","description":"&lt;p&gt;Adrian Lee, University of Guelph The non-Hamiltonian cycle decision problem is co-NP complete for which the existence of a polynomial time algorithm is unknown. In 2017, Gismondi and Lee developed [&hellip;]&lt;\/p&gt;\\n","url":"https:\/\/sites.cs.queensu.ca\/ocw2026\/event\/a-report-on-the-results-of-the-ongoing-investigation-of-the-weak-closure-algorithm-wca\/","eventAttendanceMode":"https:\/\/schema.org\/OfflineEventAttendanceMode","eventStatus":"https:\/\/schema.org\/EventScheduled","startDate":"2026-05-09T14:00:00+00:00","endDate":"2026-05-09T14:30:00+00:00","location":{"@type":"Place","name":"WLH 210","description":"&lt;p&gt;Please refer to the Accessibility page for classroom amenities.&lt;\/p&gt;\\n","url":"","address":{"@type":"PostalAddress","streetAddress":"Walter Light Hall, 19 Union St.","addressLocality":"Kingston","addressRegion":"ON","postalCode":"K7L 3N9","addressCountry":"Canada"},"telephone":"","sameAs":"https:\/\/www.queensu.ca\/classrooms\/node\/37#WALGHT-210"},"performer":"Organization"}}