{"id":321,"date":"2013-10-02T15:51:24","date_gmt":"2013-10-02T22:51:24","guid":{"rendered":"http:\/\/puzzlezapper.com\/blog\/?p=321"},"modified":"2015-07-06T11:32:36","modified_gmt":"2015-07-06T18:32:36","slug":"some-contributed-solutions","status":"publish","type":"post","link":"https:\/\/puzzlezapper.com\/blog\/2013\/10\/some-contributed-solutions\/","title":{"rendered":"Some Contributed Solutions"},"content":{"rendered":"<p>I&#8217;ve had a few solutions sent in recently, so I wanted to share them with you all. <\/p>\n<p>First, Abaroth noticed that my rhombic-cell pentomino tiling had just enough space to fill out into a five pointed star if the tetrominoes were also included:<\/p>\n<p><a href=\"https:\/\/puzzlezapper.com\/blog\/wp-content\/uploads\/2013\/09\/tetra-penta-star.gif\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/puzzlezapper.com\/blog\/wp-content\/uploads\/2013\/09\/tetra-penta-star.gif\" alt=\"tetra-penta-star\" width=\"291\" height=\"277\" class=\"aligncenter size-full wp-image-322\" \/><\/a><\/p>\n<p>But that was just the beginning! He then proceeded to produce an entire <a href=\"http:\/\/abarothsworld.com\/Puzzles\/Polyominoes\/Flexominoes.htm\">collection<\/a> of tilings with these pieces, which he calls flexominoes. One problem that can come up in tilings of this sort is that if there is a vertex with three rhombi around it, a polyomino containing all three rhombi has an ambiguous identity, since there is more than one way to &#8220;unglue&#8221; the polyomino at that point. I contributed an ambiguity-free solution to one of the patterns Abaroth found:<\/p>\n<p><a href=\"https:\/\/puzzlezapper.com\/blog\/wp-content\/uploads\/2013\/10\/flexomino-8-star.png\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/puzzlezapper.com\/blog\/wp-content\/uploads\/2013\/10\/flexomino-8-star.png\" alt=\"flexomino-8-star\" width=\"296\" height=\"296\" class=\"aligncenter size-full wp-image-323\" srcset=\"https:\/\/puzzlezapper.com\/blog\/wp-content\/uploads\/2013\/10\/flexomino-8-star.png 296w, https:\/\/puzzlezapper.com\/blog\/wp-content\/uploads\/2013\/10\/flexomino-8-star-150x150.png 150w\" sizes=\"auto, (max-width: 296px) 100vw, 296px\" \/><\/a><\/p>\n<p>Speaking of rhombuses, Abaroth <a href=\"http:\/\/www.gamedecor.com\/abasworld\/Puzzles\/Polyiamonds\/Rhombi.htm\">has been investigating<\/a> color-matching puzzles using rhombic tiles. His <a href=\"http:\/\/www.gamedecor.com\/abasworld\/Puzzles.htm\">puzzle page<\/a> has more interesting material on color matching puzzles and symmetrical polyhex tilings.<\/p>\n<p>Next up, George Sicherman sent in a symmetrical tiling for the flexible tetrarhombs:<\/p>\n<p><a href=\"https:\/\/puzzlezapper.com\/blog\/wp-content\/uploads\/2013\/10\/tetrarhomb-gs-sol.png\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/puzzlezapper.com\/blog\/wp-content\/uploads\/2013\/10\/tetrarhomb-gs-sol.png\" alt=\"tetrarhomb-gs-sol\" width=\"325\" height=\"153\" class=\"aligncenter size-full wp-image-325\" srcset=\"https:\/\/puzzlezapper.com\/blog\/wp-content\/uploads\/2013\/10\/tetrarhomb-gs-sol.png 325w, https:\/\/puzzlezapper.com\/blog\/wp-content\/uploads\/2013\/10\/tetrarhomb-gs-sol-300x141.png 300w\" sizes=\"auto, (max-width: 325px) 100vw, 325px\" \/><\/a><\/p>\n<p>What&#8217;s interesting here is that although the outline of the tiling is symmetrical, the pattern of the cells isn&#8217;t. The lesson here is that being able to trade off some cell-level symmetry for more pattern-outline symmetry can give us a little variety in our choices of what we can tile.<\/p>\n<p>Finally, Bryce Herdt provided a de Bruijn sequence of invertible length 5 binary words. (That is, a cyclic sequence where each word occurs once as a substring.) Since he did so in text format, I made a visualization:<\/p>\n<p><a href=\"https:\/\/puzzlezapper.com\/blog\/wp-content\/uploads\/2013\/10\/debruijn-invert1.png\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/puzzlezapper.com\/blog\/wp-content\/uploads\/2013\/10\/debruijn-invert1.png\" alt=\"debruijn-invert\" width=\"400\" height=\"18\" class=\"aligncenter size-full wp-image-328\" srcset=\"https:\/\/puzzlezapper.com\/blog\/wp-content\/uploads\/2013\/10\/debruijn-invert1.png 400w, https:\/\/puzzlezapper.com\/blog\/wp-content\/uploads\/2013\/10\/debruijn-invert1-300x13.png 300w\" sizes=\"auto, (max-width: 400px) 100vw, 400px\" \/><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>I&#8217;ve had a few solutions sent in recently, so I wanted to share them with you all. First, Abaroth noticed that my rhombic-cell pentomino tiling had just enough space to fill out into a five pointed star if the tetrominoes were also included: But that was just the beginning! He then proceeded to produce an &hellip; <a href=\"https:\/\/puzzlezapper.com\/blog\/2013\/10\/some-contributed-solutions\/\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">Some Contributed Solutions<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[101,127,128,10,71,33],"class_list":["post-321","post","type-post","status-publish","format-standard","hentry","category-recreational-mathematics","tag-de-bruijn-sequences","tag-flexible-polyrhombs","tag-flexominoes","tag-pentominoes","tag-symmetry","tag-tetrominoes"],"_links":{"self":[{"href":"https:\/\/puzzlezapper.com\/blog\/wp-json\/wp\/v2\/posts\/321","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/puzzlezapper.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/puzzlezapper.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/puzzlezapper.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/puzzlezapper.com\/blog\/wp-json\/wp\/v2\/comments?post=321"}],"version-history":[{"count":3,"href":"https:\/\/puzzlezapper.com\/blog\/wp-json\/wp\/v2\/posts\/321\/revisions"}],"predecessor-version":[{"id":329,"href":"https:\/\/puzzlezapper.com\/blog\/wp-json\/wp\/v2\/posts\/321\/revisions\/329"}],"wp:attachment":[{"href":"https:\/\/puzzlezapper.com\/blog\/wp-json\/wp\/v2\/media?parent=321"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/puzzlezapper.com\/blog\/wp-json\/wp\/v2\/categories?post=321"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/puzzlezapper.com\/blog\/wp-json\/wp\/v2\/tags?post=321"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}