Python super-simple explained solution, faster than 95%
Like it? please upvote...\n\nclass Solution:\n    def longestWord(self, words: List[str]) -> str:\n\t\t\t# helper function to check if all prefixes are in dicti
**Like it? please upvote...**\n```\nclass Solution:\n    def longestWord(self, words: List[str]) -> str:\n\t\t\t# helper function to check if all prefixes are in dictionary:\n        def check_pre(word):\n            for i in range(1, len(word)):\n                if word[:i] not in words:\n                    return False\n            return True\n                \n\t\t\t# sort by reversed lexicographical order:\n        words.sort(reverse = True)\n\t\t\t# sort by length of word:\n        words.sort(key = lambda a: len(a))\n\t\t\t# go through all words from end and check prefixes:\n        for word in words[::-1]:\n            if check_pre(word) == True:\n                return word\n        return ""\n```
['Python3']