RubiksCube.docx

RubiksCubeIthinkalmosteveryoneknowthistoy.Andmanypeoplehavetriedtosolveit.11isoriginallycalledtheMagicCube.WhenIwasalittleboy,myfathergiveittome,andheshowedmehowtorecoverythefirstlayer.Atthattime,IwasamazedbythatbecausenomatterhowhardItried,Icanonlytomakeonesurfaceinonecolor.SoItrytofindouthowtosolvethefirstlayer.Yousee,itisdifficultnottoplayMagicCubewhenyoufirstmeetit.WhenIwasgrowingup,IknowmoreaboutMagicCube.Itisinventedin1974byHungariansculptorandprofessorofarchitectureRubik.Itiswidelyconsideredtobetheworld,sbestsei1ingtoy.AstandardRubik'sCubemeasures5.7cmoneachside.TheoriginalRubik,sCubehaseightcornersandtwelveedges.Thustherearemanypossibi1ities.DoyouknowhowmanypossibilitiesofRubik,sCube?Itisapproximately43quintillion,eighteenzeros.SoIfyoudonotfindawaytosolveit,itisveryhardtorecoverybylucky.ManygeneralsolutionsfortheMagicCubehavebeendiscoveredindependently.ThemostpopularmethodwassoIvingthecubelayerbylayer.Thissolutionisalsocalledsevenstepmethod.Anothersolution,whichisso-called'CFOP',commonlyusedbyspeedcubers.Thecrossisdonefirstfollowedbyfirst-layercornersandsecondlayeredgessimultaneously,witheachcornerpairedupwithasecond-layeredgepiece,thuscompletingthefirsttwolayers(F21.).Thisisthenfollowedbyorientingthelastlayerthenpermutingthelastlayer(O1.I.andP1.1.respectively).CFOPrequireslearningroughly120algorithmsbutallowstheCubetobesolvedinonly55movesonaverage.AsIsay,therearesomepeopletrytosolveamagiccubeintheshortesttimepossible,Wecallthemspeedcubing.Thereareanumberofspeedcubingcompetitionthattakeplacearoundtheworld.Sotherearesomerecords.1.ikeasSingletime,singleshortesttimetosolve.Itis5.55s.Averagetime,theaverageminimumtime.Itis6.54s.Andshortlybefore,someengineersusedtheGalaxyS4asrobotsprocessorwithin4secondstorecoveracube.Thisisthefastestrecord.Inaddition,peoplewanttoknowhowmanymovescansolveanymagiccubeatleast.Theyusedsupercomputerprovedtheso-called"God'snumber”tobe20.Thisisoptimal,sincethereexistsomestartingpositionswhichrequireatleast20movestosolve.Bytheway,themagiccubethatsettheworldrecordisinventedbyChinesecuberDayantou.Thecube'sstructureisdiFferentfromtraditionalone,butitisbetterforusing.sforme,IhavelearnedtheCFOPsolutioninsixmonths.Soifyouhaveanyinterest,comingtoaskme.