LeetCode 792：匹配子序列的数量求解错误求助

题目理解与初始解法 #

我对LeetCode 792题的理解：字符串abc的合法子序列包括a、b、c、ab、ac、bc、abc；不合法的子序列如f、gh、bb、cc、ca等。基于这个理解，我想到的简单解法是统计原字符串中各字符的出现次数，遍历每个单词时检查字符计数是否足够，若字符不存在或计数为0则无法构成子序列。

初始实现代码 #

from collections import Counter
from typing import List


class Solution:
    def numMatchingSubseq(self, s: str, words: List[str]) -> int:
        total = 0
        counts = Counter(s)
        for word in words:
            seen = counts.copy()
            for char in word:
                if not seen.get(char, 0):
                    break
                seen[char] -= 1
            else:
                total += 1
        return total

题目要求 #

给定字符串s和字符串数组words，返回words中是s的子序列的字符串数量。子序列是指通过删除原字符串部分字符（可删除0个）且不改变剩余字符相对顺序得到的新字符串，例如"ace"是"abcde"的子序列。

示例 #

示例1 #

输入: s = "abcde", words = ["a","bb","acd","ace"]
输出: 3
解释: words中有3个字符串是s的子序列："a"、"acd"、"ace"。

示例2 #

输入: s = "dsahjpjauf", words = ["ahjpjau","ja","ahbwzgqnuk","tnmlanowax"]
输出: 2

失败的测试用例 #

s = "ricogwqznwxxcpueelcobbbkuvxxrvgyehsudccpsnuxpcqobtvwkuvsubiidjtccoqvuahijyefbpqhbejuisksutsowhufsygtwteiqyligsnbqglqblhpdzzeurtdohdcbjvzgjwylmmoiundjscnlhbrhookmioxqighkxfugpeekgtdofwzemelpyjsdeeppapjoliqlhbrbghqjezzaxuwyrbczodtrhsvnaxhcjiyiphbglyolnswlvtlbmkrsurrcsgdzutwgjofowhryrubnxkahocqjzwwagqidjhwbunvlchojtbvnzdzqpvrazfcxtvhkruvuturdicnucvndigovkzrqiyastqpmfmuouycodvsyjajekhvyjyrydhxkdhffyytldcdlxqbaszbuxsacqwqnhrewhagldzhryzdmmrwnxhaqfezeeabuacyswollycgiowuuudrgzmwnxaezuqlsfvchjfloczlwbefksxsbanrektvibbwxnokzkhndmdhweyeycamjeplecewpnpbshhidnzwopdjuwbecarkgapyjfgmanuavzrxricbgagblomyseyvoeurekqjyljosvbneofjzxtaizjypbcxnbfeibrfjwyjqrisuybfxpvqywqjdlyznmojdhbeomyjqptltpugzceyzenflfnhrptuugyfsghluythksqhmxlmggtcbdddeoincygycdpehteiugqbptyqbvokpwovbnplshnzafunqglnpjvwddvdlmjjyzmwwxzjckmaptilrbfpjxiarmwalhbdjiwbaknvcqovwcqiekzfskpbhgxpyomekqvzpqyirelpadooxjhsyxjkfqavbaoqqvvknqryhotjritrkvdveyapjfsfzenfpuazdrfdofhudqbfnzxnvpluwicurrtshyvevkriudayyysepzqfgqwhgobwyhxltligahroyshfndydvffd"
words = ["iowuuudrgzmw","azfcxtvhkruvuturdicnucvndigovkzrq","ylmmo","maptilrbfpjxiarmwalhbd","oqvuahijyefbpqhbejuisksutsowhufsygtwteiqyligsnbqgl","ytldcdlxqbaszbuxsacqwqnhrewhagldzhr","zeeab","cqie","pvrazfcxtvhkruvuturdicnucvndigovkzrqiya","zxnvpluwicurrtshyvevkriudayyysepzq","wyhxltligahroyshfn","nhrewhagldzhryzdmmrwn","yqbvokpwovbnplshnzafunqglnpjvwddvdlmjjyzmw","nhrptuugyfsghluythksqhmxlmggtcbdd","yligsnbqglqblhpdzzeurtdohdcbjvzgjwylmmoiundjsc","zdrfdofhudqbfnzxnvpluwicurrtshyvevkriudayyysepzq","ncygycdpehteiugqbptyqbvokpwovbnplshnzafun","gdzutwgjofowhryrubnxkahocqjzww","eppapjoliqlhbrbgh","qwhgobwyhxltligahroys","dzutwgjofowhryrubnxkah","rydhxkdhffyytldcdlxqbaszbuxs","tyqbvokpwovbnplshnzafunqglnpjvwddvdlmjjyzmwwxzjc","khvyjyrydhxkdhffyytldcdlxqbasz","jajekhvyjyrydhxkdhffyytldcdlxqbaszbuxsacqwqn","ppapjoliqlhbrbghq","zmwwxzjckmaptilrbfpjxiarm","nxkahocqjzwwagqidjhwbunvlchoj","ybfxpvqywqjdlyznmojdhbeomyjqptltp","udrgzmwnxae","nqglnpjvwddvdlmjjyzmww","swlvtlbmkrsurrcsgdzutwgjofowhryrubn","hudqbfnzxnvpluwicurr","xaezuqlsfvchjf","tvibbwxnokzkhndmdhweyeycamjeplec","olnswlvtlbmkrsurrcsgdzu","qiyastqpmfmuouycodvsyjajekhvyjyrydhxkdhffyyt","eiqyligsnbqglqblhpdzzeurtdohdcbjvzgjwyl","cgiowuuudrgzmwnxaezuqlsfvchjflocz","rxric","cygycdpehteiugqbptyqbvokpwovbnplshnzaf","g","surrcsgd","yzenflfnhrptuugyfsghluythksqh","gdzutwgjofowhryrubnxkahocqjzwwagqid","ddeoincygycdpeh","yznmojdhbeomyjqptltpugzceyzenflfnhrptuug","ejuisks","teiqyligsnbqglqblhpdzzeurtdohdcbjvzgjwylmmoi","mrwnxhaqfezeeabuacyswollycgio","qfskkpfakjretogrokmxemjjbvgmmqrfdxlkfvycwalbdeumav","wjgjhlrpvhqozvvkifhftnfqcfjmmzhtxsoqbeduqmnpvimagq","ibxhtobuolmllbasaxlanjgalgmbjuxmqpadllryaobcucdeqc","ydlddogzvzttizzzjohfsenatvbpngarutztgdqczkzoenbxzv","rmsakibpprdrttycxglfgtjlifznnnlkgjqseguijfctrcahbb","pqquuarnoybphojyoyizhuyjfgwdlzcmkdbdqzatgmabhnpuyh","akposmzwykwrenlcrqwrrvsfqxzohrramdajwzlseguupjfzvd","vyldyqpvmnoemzeyxslcoysqfpvvotenkmehqvopynllvwhxzr","ysyskgrbolixwmffygycvgewxqnxvjsfefpmxrtsqsvpowoctw","oqjgumitldivceezxgoiwjgozfqcnkergctffspdxdbnmvjago","bpfgqhlkvevfazcmpdqakonkudniuobhqzypqlyocjdngltywn","ttucplgotbiceepzfxdebvluioeeitzmesmoxliuwqsftfmvlg","xhkklcwblyjmdyhfscmeffmmerxdioseybombzxjatkkltrvzq","qkvvbrgbzzfhzizulssaxupyqwniqradvkjivedckjrinrlxgi","itjudnlqncbspswkbcwldkwujlshwsgziontsobirsvskmjbrq","nmfgxfeqgqefxqivxtdrxeelsucufkhivijmzgioxioosmdpwx","ihygxkykuczvyokuveuchermxceexajilpkcxjjnwmdbwnxccl","etvcfbmadfxlprevjjnojxwonnnwjnamgrfwohgyhievupsdqd","ngskodiaxeswtqvjaqyulpedaqcchcuktfjlzyvddfeblnczmh","vnmntdvhaxqltluzwwwwrbpqwahebgtmhivtkadczpzabgcjzx","yjqqdvoxxxjbrccoaqqspqlsnxcnderaewsaqpkigtiqoqopth","wdytqvztzbdzffllbxexxughdvetajclynypnzaokqizfxqrjl","yvvwkphuzosvvntckxkmvuflrubigexkivyzzaimkxvqitpixo","lkdgtxmbgsenzmrlccmsunaezbausnsszryztfhjtezssttmsr","idyybesughzyzfdiibylnkkdeatqjjqqjbertrcactapbcarzb","ujiajnirancrfdvrfardygbcnzkqsvujkhcegdfibtcuxzbpds","jjtkmalhmrknaasskjnixzwjgvusbozslrribgazdhaylaxobj","nizuzttgartfxiwcsqchizlxvvnebqdtkmghtcyzjmgyzszwgi","egtvislckyltpfogtvfbtxbsssuwvjcduxjnjuvnqyiykvmrxl","ozvzwalcvaobxbicbwjrububyxlmfcokdxcrkvuehbnokkzala","azhukctuheiwghkalboxfnuofwopsrutamthzyzlzkrlsefwcz","yhvjjzsxlescylsnvmcxzcrrzgfhbsdsvdfcykwifzjcjjbmmu","tspdebnuhrgnmhhuplbzvpkkhfpeilbwkkbgfjiuwrdmkftphk","jvnbeqzaxecwxspuxhrngmvnkvulmgobvsnqyxdplrnnwfhfqq","bcbkgwpfmmqwmzjgmflichzhrjdjxbcescfijfztpxpxvbzjch","bdrkibtxygyicjcfnzigghdekmgoybvfwshxqnjlctcdkiunob","koctqrqvfftflwsvssnokdotgtxalgegscyeotcrvyywmzescq","boigqjvosgxpsnklxdjaxtrhqlyvanuvnpldmoknmzugnubfoa","jjtxbxyazxldpnbxzgslgguvgyevyliywihuqottxuyowrwfar","zqsacrwcysmkfbpzxoaszgqqsvqglnblmxhxtjqmnectaxntvb","izcakfitdhgujdborjuhtwubqcoppsgkqtqoqyswjfldsbfcct","rroiqffqzenlerchkvmjsbmoybisjafcdzgeppyhojoggdlpzq","xwjqfobmmqomhczwufwlesolvmbtvpdxejzslxrvnijhvevxmc","ccrubahioyaxuwzloyhqyluwoknxnydbedenrccljoydfxwaxy","jjoeiuncnvixvhhynaxbkmlurwxcpukredieqlilgkupminjaj","pdbsbjnrqzrbmewmdkqqhcpzielskcazuliiatmvhcaksrusae","nizbnxpqbzsihakkadsbtgxovyuebgtzvrvbowxllkzevktkuu","hklskdbopqjwdrefpgoxaoxzevpdaiubejuaxxbrhzbamdznrr","uccnuegvmkqtagudujuildlwefbyoywypakjrhiibrxdmsspjl","awinuyoppufjxgqvcddleqdhbkmolxqyvsqprnwcoehpturicf"]

内容的提问来源于stack exchange，提问作者watch-this