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1、RubiksCubeIthinkalmosteveryoneknowthistoy.Andmanypeoplehavetriedtosolveit.11isoriginallycalledtheMagicCube.WhenIwasalittleboy,myfathergiveittome,andheshowedmehowtorecoverythefirstlayer.Atthattime,IwasamazedbythatbecausenomatterhowhardItried,Icanonlytomakeonesurfaceinonecolor.SoItrytofindouthowtosolv
2、ethefirstlayer.Yousee,itisdifficultnottoplayMagicCubewhenyoufirstmeetit.WhenIwasgrowingup,IknowmoreaboutMagicCube.Itisinventedin1974byHungariansculptorandprofessorofarchitectureRubik.Itiswidelyconsideredtobetheworld,sbestsei1ingtoy.AstandardRubiksCubemeasures5.7cmoneachside.TheoriginalRubik,sCubehas
3、eightcornersandtwelveedges.Thustherearemanypossibi1ities.DoyouknowhowmanypossibilitiesofRubik,sCube?Itisapproximately43quintillion,eighteenzeros.SoIfyoudonotfindawaytosolveit,itisveryhardtorecoverybylucky.ManygeneralsolutionsfortheMagicCubehavebeendiscoveredindependently.ThemostpopularmethodwassoIvi
4、ngthecubelayerbylayer.Thissolutionisalsocalledsevenstepmethod.Anothersolution,whichisso-calledCFOP,commonlyusedbyspeedcubers.Thecrossisdonefirstfollowedbyfirst-layercornersandsecondlayeredgessimultaneously,witheachcornerpairedupwithasecond-layeredgepiece,thuscompletingthefirsttwolayers(F21.).Thisist
5、henfollowedbyorientingthelastlayerthenpermutingthelastlayer(O1.I.andP1.1.respectively).CFOPrequireslearningroughly120algorithmsbutallowstheCubetobesolvedinonly55movesonaverage.AsIsay,therearesomepeopletrytosolveamagiccubeintheshortesttimepossible,Wecallthemspeedcubing.Thereareanumberofspeedcubingcom
6、petitionthattakeplacearoundtheworld.Sotherearesomerecords.1.ikeasSingletime,singleshortesttimetosolve.Itis5.55s.Averagetime,theaverageminimumtime.Itis6.54s.Andshortlybefore,someengineersusedtheGalaxyS4asrobotsprocessorwithin4secondstorecoveracube.Thisisthefastestrecord.Inaddition,peoplewanttoknowhow
7、manymovescansolveanymagiccubeatleast.Theyusedsupercomputerprovedtheso-calledGodsnumber”tobe20.Thisisoptimal,sincethereexistsomestartingpositionswhichrequireatleast20movestosolve.Bytheway,themagiccubethatsettheworldrecordisinventedbyChinesecuberDayantou.ThecubesstructureisdiFferentfromtraditionalone,butitisbetterforusing.sforme,IhavelearnedtheCFOPsolutioninsixmonths.Soifyouhaveanyinterest,comingtoaskme.
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