我写了一个脚本来从上到下而不是从左到右读取一个大字符串。当我运行代码时,我的 CPU 的一个核心卡在 @100% 上,并且代码永远不会完成。如果我取消对 console.log 的注释,它会越来越慢地吐出字母,并将所有 8 个内核固定在 @100%,内存使用率会缓慢上升,直到用完我系统上的所有 8GB,然后它会因 OOM 错误而崩溃。我显然做错了什么。
var haystack = 'SRASBPETHWTWHDZVPOAECJHGNXHRKZXRBMSDYGZGNZBBCOKVPPJKKAQECOLGBFIIKTPVSROCCWWGRWDEQTNFSKEDNFBFKWVEELVTBULWROMGTXSASKCTFJQFDOGRNMZEBLFSCFAFWXZVRGFAZHERUTMOETZZRYNUHSRTHEYIVQDXFNWDDSLSSGPFOMYRHBGKONPIWDTZUBBRAJZGBVUGMVZZTPRAXMLZSXYELKJZWXUYUQIUGGHISZHIGSUQHGHTICVWIJVXMUXOQHPDESKSPRJHQVVTRTNQEVUWKGGQDURAXZWTMYUYIISIOXLTHCISFFSNHZMCGEWMOWCHRQKYNDTDLFWERZLEPRLTNZSPFEDCDESQVMLWMXGCXPMSPTJGSXTXINFADZTBUNDIQWOAIGFKQAJWHINHMZCZVMTJJWGTSGGOIBOZCJGVURJETNXSXWEDUNJPVLPZTDIMSIZGQUJALJYWVLRDYDRWVHZNUNKOLAUPTBMKUNFQYLVQKOQIPPWVNDXENRCVABOTNEKKJPURYNAWAGIZFEHYQMOFICBCQKELTMUYVQPYPZKVBYPTLXRLMYEXGAPRCWDJHQASDQHRGSTIYGMEAWOBLFPSDBGGXFBGIARMGLYOFCZXILLFLCVKCKCXYBTKIYRHLPWXBNGLJYVIZHWPIQSQLHURYRRTBTUBYRMMEQULVVJFKRRZTZVOIKNXPIICBQGFPTETWVPVUKEQOVTCOUARDTAVZFSZWBSTWTQEGLIDKUVMTFRXHOWPPJHCEWMTHJRKXENFENKDMPEYVNEMQRDBGZDIBVYCCFLFMFPSXHHADOZWMMOJKQSYNAPOKLUPSALZVKPKVBRIAFOXSECFCULWPFNPKFGIBPAUEXEOHLTRWTLJMHEMIXSVZVRYZQXCUGNZGDSLXJSROSBAIWPKQGICVKSMAVUHZPIQHDQGLSMJUQYYAZQSVORXLRNMEOYUFAKGKHJFKQPBYKDSLYHKLCEWAQINPRGOGVCQBAKTVDZZNRSIKZVSRMFCDJSANSGNQZPPEZSIZCSQCPMIRBKJZFKVRVVNOLDSYGFLMNJHCGUZDRVHTLSJMCHZCQJUURVMEFABDKQEFYXYZEQUOLEOZWXDXXOXIFPLTFBGTKYTBVSSTJESKVIMHJSUDVKRKOJYOGWIXLODESHRMPYBWKRPFEUGIYXXGHDVYXPUBVSQPHRUSSCQDHAXMJNUNSFGHZANXDFFXDETLXVAUAPOCASOTONXBXIYFMSMUUPFGMYKWVFGTTQFSNUDFTIRWSVVEQHPVFRYPLGPGIEUMSSFONCONOPHSDWGFBIGPEKQBRPZWYLZLKCMWFOKLNQBYJREVFRLWFBDVIVIIVZUTQZOLDSNDUISKYGJTIGWYUQBXXTAPQMKULPXGCYFMZLNQDAWOBWOVTKXOABKZRWAZUDYYTYNDQAEJHEDPOYUANKWMUATXGCRRGEKDVTIGTFLQHQVFJBRIFKYLHDJUXLAMVELRZPNBSEBQUVHARMKVCLLDHHYYQNTXFIMFKRIMTJUEJOWIEIETZDADSGNJFDGGWKRJUXQXXKLOUSYMCTHLYIXSICFCRHFCXUSFOMCVSVYIIMCNEGHRMCZKWXPHFAMCTCBEBHQOBDXHAYNSVVZWAGTEIMVWRCCPNCCQGUWXIGCPZERUVJRQIZQYSMAUNHCVNROCDFORLNOWTLVTHADALVCOISZDFKNFMXQBMVUMFDFKDGNRQKZPXDJNZODBXFUAGEPCEQSLGAOSQZUHJXEQFTRLAWZUUROTADFEXJBGJCOPLRNLLHVTNPNPHJDYWEGBKVOZOFDYMYMHUNDMLIZOCLODMRBZORXZVTUAIDXZIGOLLMGUJLSOHSVDFEMDTXEUMIOITNSXVNXUWMNPFITZXAJBKUVMNLUOONUDQSWYUCZOZXOXAFRCWVMMBLFCPPHFTLEKHXQNWYMQYDLGHTSSGDCFIRSMVTJFKPLVLBWIFWBJQTKXBIMLRTGNABJDXWIEFLVCDLQTSWURMBASDXNXHBQTEBCUTGWVTHXDHRJYZZKNQEBPXRYMWAXEGRSRUCQHYIOVOYJUXPANVEAJEUKKYAWEZSPZYCQPPWXVNNPHIVSHSSYVJLUNDXAFPCXLOOTRYVLVGNIQVPZLBXAPWQGSCCXINWFTIVFGLMUTPRWQFJORMQYYIUUJZRLLFXATWFRCQDKDIFXZHCWJGYEROPRQTJGJJSTRRKAMAGGMZKKOPXYKUSNZVVHHNRAGAGWXZOIYKVMAQJELXWGUEWMTSJMOEZRUEGUBZELODZNCDASJZGOTXYZGVTVMRTVVSWHFEFVUJPCCGEJXWYYLBVZGIGCHRNQOEDELTDIUZPAGGJYPCEEKZNQSMDKNMRZFVBPLIRBFCCVLUGCVPLOPCWDZJZAMKFKRLXTKQJIZSNAQFUXMCLXPTBKNNWWKKBVLYQPFHVEHGXQEHPOWRIIWXGKVBFMMDOJNFMCCNWTALOTLCMFKXKGIKYHQIOUJOAIXEFIMWMKCTABKRCVTAFDLWIQFDUEYDOBFJOKXBKIIBCVIVILAWTFXHLUVTMGQEJEVKBAVMITJPVRGRCDSFLPXRFWGAJLGMSPAOUVMDUBXYWEOVMDNUOIMXGEVNKCALLWPPMNNMFOVTZOAPSDJFZECSDIHKXCYJCAGYKLPOWFTVSRDSBSGGWDNFSTRZQYKMOUDNTRGXFKJBLOECLUJQGRQWGUETMKOGUWCAHDHGGCBSWXTXMLJMJFJTKURTTCXNOOEBYYUVKPWXSNUKVCZOXJOMXXCLTZWBUDYMEJNTIPBTWJKJJLYQFGYRGYFUCTAICLKBYEHONSPSMXLLMZCMJQVOGKEZOYBDJIUHAFGCEIAPXAQVGSBIJVUDHTWPPEKMWWFEUCAQWFRHLCFTLPXVJNKFCTEXGKPZXQXOBKPDWOAFOZTBYGDVFAJXMQOHAPTLSNLKJIGZRFSBGMQBNBAHELRDEWUEWQVKVYZBPGQVOWYKZEGLJRLYHBETRZTEWBTGJBRUTBKNDGEAQEUTLZZSAMCMMVJWBPDKOSGPLVUKPZAQGJDKUIIPCVBOIBCXRAAANQSCBBYQNXRTCRNHJGMRYICLHDBXVXEGBFAEXOAABYDXFQTKPXVMQPHXLTXCVMLXDJPULJNOGVZFMYIRBFIEESIEJDBLYPARQERLKUEHYUGJIRKVQEFZLQUQXSKRNBZURWPLZSTPXISSJLUFZSMFXZIVESRSKEDNJEPGVPUBHLGWTKISYYJVQHXPHJDWDWQMAQWTZIBKCHEAETDYBJETTGZYHUURVERLLSCKUHSJMOAXTRYGKDXGISNNAHVQTEZKRKWAMMHAJGEJZOWZNEIZLZSSGLDGHXNEJPUBPPXNLJCKBFYDGXUPXITFATASDFNSHKWNZMQGXBBOSHEWBOWWCFKDCWVKWOTKMNEGJNOPURJJWAFPQOLNGBMAUCITMGZBOQIEUJEIOSNSMYQJTGVPFGXWCCCKDRRVDIHDYCTQHESHCTUUSSVQWMWTAOKIJALBPMGBEXZQFRIKAQVWBUXUNKBYMYSEXBNZHFHUSFGSKRQYZVKTALOHBMXSGHRUDUYSSMWFMPMMWFXCPISMWXIFEQSWTQQKUMZGOANSOASHGJBEKWLJBXENHHBWQQUCRQYNAATEWLTESGXPCWYFVQGGXTTPIBWSYRXBQGDXJMZFQRYDPKFPNYRQEFGFSZBGZRDVLHSYXTRTXFOIQIYBPFEXQDXBEPJNDPPBICIRTBBTLQUALXYUWPUDBVMJSOJPNEGIWXGCBFDZZSKWNAUIAXOVJJWULADOMBTGOTCIAYLIAGYTVVBZVVMYBWAJYQYCTNHUXYINPLAEIJCECYYBFIMUXXDGRKJADAFWWQKVSKLWKGPJPFZDCWNIHLERAIXHDIIIMDQPFTZVZTWYXYCUOCFFEYPBZRTSCPUQMWXGZVYCKTEVNJPBDUBXIUSUOOGGYGRTGAZTYRCGBKJFGXBRMDQGZXIGZDJCHWFORQKJJGUJTRIGIKOBYSRTIOUIAZWVHAWISDDWTICHGVEHSUTDFTGBIJUMXLNHLVXBOFPCEUOWQRDIELVYBAOAWLRCBJVKJCXYPJPGIJGNGJYUVFDNDCDBQXQMRYLIHDKYQHGBWBZOAOXPMALQZEWAAHGMSLSROAJPLGSIKFUSYRDJPQCOOQJTJVNPLIHJECIFUHIIEZYMJCQTCKUHSCJMUVDEZIMFEGOMRHVUVIVGMBERRPLGKWWOPLKRQIWJRZBYOSXROTLBUDGLWGKKWANWWIWJNQDCVOBSIPNXJEHKNUHSXCXDCCRSNBYZVXBUOAETHRQYYVQGLXWBWXYDRBFSBCNOSJHGTNSCIAXPCLOACAQGCBTXZGTCIDNGLAZCWXIFWKDYJWBKXDEUJZPQRLWASIKLSLFMERFKPXQYQFIRYHHUXSCWVLQZGSMLZUYOAFCUHMJIVDOEBHDKZYUDADMCHXQYIKUMKAPRPWSGDMNAGCSOOVPSCSWCENPBOCCJQXPBBDEHHVUVTFSLHGTKHASWGOUUQEDZYJOXUXELQAMKVNGAAJXMAHKARSLPRZGTDBKPRCXYHWWHWRRXXPRFKMJJNEYGHTMWCTNBQRCUAJPPPLPNJETEYDBRMLEIKLKGLJMUBPRLWIFEOOQCBGNOVMLMTZGYCGMSLCTKBVHJGUZLGYUJYXONOPRHMJEAHICJRUXILJAGNHHJXSLJTVMGGRNVKTDOJVHHXWZVJIEJCPPVKAVHWPCNBZTIMNVYGAKBJIGBNMLRAYUAHKJWCOISZHMGONXQAXWJZVQOGQUGAKJEXUNLTCDYRQWDGGOUUUUHWPRASTBFMSYGROSNLXLENLVETJKKSOLSMHVEUQRLJUDAMKJLWECCIHTUSPPTVXUVZZVDUVPVWNQUPLIHVDPUQVUIIGIYCFUANGHNOWQMSOQOMHLQNIKVQBGOQHHZFVCLPIYOXHIAXDLRZJGXAIJYNLVXEIAAIZXCUITPLABHDPJYZEOACHCRYUZNYNHPJPOPPGEKXJAAZLGPXJSNHNSQSPJRXZGYGSNDUWNJCQNPLJJGKIBUXGSPGUXZAWHYBWCDSQPWVTBCVDQRDXMXBMDVRXLPHGUFSTQPXOLOFIZKFDLJSUUUXCINQOYFULWDNUZCRJIOSRMOWVMMHNYNFBUKYXEFLIPBFEDPFJGHFXQYVUZBUNUJDLSWYREVCKMVQQVAATSRNUOSNABSMXRFVVMVTXITIYWUKTCDNZPYUGPPQOQRPDFMVUXMTKNZQWOJHWELRFYDFKTBGVVSZNBTDNPBFHAKKUFHZVUXRARYEKWUCYQXLIWONVNBYXNAQZBTVGWIDGTAWFBRMRVVKYAXJOTYYSQXZAJEOWWCOJXLBWSXGODJSUEOMYXHPUEPDYLWYJNDISRWYYFAGYMVSXPTGTTVWTFBSTFMFCYRLFISMGKAZVQBSNISILDCSLUGVWBBKWAXOPTHPJQFBTONDUMCCNEDSRBYOCIAMTLBAVESZQEAHGNFADENFWGWIGAQTOCSNXNSZNEVJMHVENBGUOOMMGCBGJBCPQPYMBHDKJPQDBLAMLLSGUEEFLNGNZJFQFZKONNDHXIUJDMBUNOVWSFBBJWRHIJSTMSQNSFPDJAXRARKGEDQDHWGZQWZRWPLWAUPUIGUXPAXHIKPDJLCQOMHRYRLJYOCSNAWRNCHSXHJTKNGMHYOHRFIYQJFSPJOMYBUPHUQJRWNQEESRWPGJKHZRNDZBQIQBNFSIAVIBDEWWSDRATKVZPBTTHJYASFTUCIIHZQTXEOTLJSVTZQWALTTBGQLPFSYITRVWMKCJOZWONQSZTPDLXESINYENYTAZYPVZPDBYGFDGEZTJPZVZDHTRKOTGZELUGEWSMYZFOSQEZNNSCVKWXCKBDDRMWFWUBJJHTVQVPARGEFMXCCKQLCOABKJYOKUPJYQNMKNDBNROJDPUANZUTBZRKPCOFJHKHJQWQZMNFOLTJVODPWFPJOEYBLPIOIWFQOETPAAZEHMYSNMSSFSTIWOZRTGGXHDKJPOKCDUCFOZJNQAUUZJONRAOJHVPQDMUHNFRBHECDFCAOLXXQBDEPIZWQHMONFDLDQDAHAZRHGJTXVUPDPZVNHJHSGBPMVFVAHYUYKRPQVSTNSQXEBMSSKJBYQKBXWSNAQZJSYPQDCRFORMTTBVWUBPYIXLLMZEOMAELSCBIMRASXWFFFFZDHEUDIRZKJMNNENEARMVLNGYGJMCAOWYICCTRIQUJAWWLAPFTBJGHHEHBVQJNIDKAGMPOLTZIKEEBQTQHFVDIAHJEZMIFWPMXTEHJQKGMHMMYPYQCARDOZERLTHGYWWJJEILSYLISWVPRSCIUXVXKSQWLKTRCWUURCLGXYQQXWQVOWXTLURZIKQRJXTPNWRNQAYMIMMUXCTZREGGHFXMMAAHZZMQIEQGBHORJGAAZAJNZIDKKXZIRRTUASAEOBPBWYDUCUILWFEUMSBCPWWMNDCEFNSDJBGVDYUOUPPLEMTQLOLVXLPFNMYNCTSSIJRLQDOWSUEREYCVPKJVBTAVKEANLCJVZHRUIOEWBCUYDLEYYDLYEYYMOUTROZIGJRHRNLISBLUGUNLZZLNHIWTDNGRLAVPOLOYSMTTLLPKDLQWNSXMIDXBHAXYEMRPYONJVJLYPFLMLOSLWTRMSHLYMSRJHXKXRGWGAIXBUCWRXCGEUWYUIUSQQPWKMHHSBDFSYZKOSQZXXAVXXXJKFCNIGXEQZNBBKEKCQOWQGQHTUIPEYUFJARTKKFHDOUHLHUZZFXLWHIOOIGKNPAXEXDNWIUQSOSBHDEQLKPLIRUQMUBHSQIGUNJSBWHLBFSUOTNJZWQDDXETAQNDYADEIGPJEBVGIDGLVDMIECXNUIELRZAUFRBSMNPOGJHHCDAVVKIYEOWLLAVCUZOCBDKPAPCUVHWXUQSUASGIBQAOROBZLGTAMIHSHOWXPQBVFCOSNQLMFGEZAZRXTIHWDWXATHYUAIDPSGBPUIVVROEXXUHHVCCCMNXFGAQIJNNVZHBEWULPGLYJHLRBFGPPJCAIAFKALYQDWBFGDYRCOQGXZLVLSMMDXEKDCMQIQBQVRGVHTYUZTHGATYRZVIGUMKADPIGSIFJZCKKJHEONIKRXKOPXAGMWBMHVPVPDWRADGMTVERKRWSSVLVFIJGMUBZTRSPNGDLFRBXGMHNEOJCMPFOAPWEPLGRABYLLXDLTERRBKDBVYGQNDYYNCHLWDWWYLLVQBOVIHFJLFVTMKDVINYKKERJKSCZTZEKQSFOSMPNVGSNQSQNDAVQJNNLQHJLBTXPZBXFYRRACYWMCKFORKWGNJCLFIXCIQSPWUWTRLJSICZVKZDAIQTURXNBGDLIREHDLDUCDNDXNSHRCLQLATVPHOZRTIXXIQYEJSARNKOOYIIFVLEGISMMEQNCMAKQLXRQRNEKMGFLCNCJWCTRDMEIFCZVJGTLGWDSTBSEUKVWEIHOHMSZKXUCCVHACKLKQJQSXKUJXPTSHKYRMUADWABQSVKIPFRPTDASYVGJXXMSHFNGRDXIQFGCUGHLKOWXPJETKDWUZHZFKEDYTKZEUUQDIJMWKYUVDYZPTWSHNJDBLZMNOTKGCWFRASJBPQYPTAKPDBFPFLZCEPKPTHTQAQVMMFXUUNEGOJOYRCSBIZZPEREIYMQYMBJIDTYCJAJVIQGHLHVYVLFXRJJWEJJEGVJOYCBVQEVXKEDKLRFSOMXWEKBCHEMLCIVTZXXTJOXHPZAIMBTJBHVSOGNWZBRFABAINEEBPWNYSBENBURPTRCAYWKCQCNZXWKRWVLVTHJWSOBEWANCJSLRWZOBPNITSTYNTVJJZNCNSPCFDQQNAMMQPVPQWTBPSAMWZECDXXCKBBEQKSKLALCZRZCNFDYOXEAYHHKRNF';
for ( var n = 0; n < 64; i += 1) {
for ( var i = n; i < 124*64; i += 64) {
//console.log(haystack[i]);
var vertical = vertical + i;
}
}
console.log(vertical);
但是什么?我对这个大字符串和同样大的数组进行了其他 (indexOf) 操作,性能还不错。这个嵌套的 for 循环是不是一件令人讨厌的工作?应该怎么写?
最佳答案
这与字符串无关,您甚至没有访问它。
您搞砸了索引变量,循环永远不会终止。您从未在任何地方尝试增加 n
,因此它永远位于 0
。
关于javascript - node.js:嵌套for循环,字符串操作性能惨淡,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/21107043/