[LeetCode&Python] Problem 720. Longest Word in Dictionary-优快云博客

本文介绍了一个算法问题，即在给定的单词列表中找到可以由列表中其他单词逐字符构建的最长单词。通过示例和代码解释了如何解决这个问题，包括在多个可能答案中选择字典序最小的单词。

Given a list of strings words representing an English Dictionary, find the longest word in words that can be built one character at a time by other words in words. If there is more than one possible answer, return the longest word with the smallest lexicographical order.

If there is no answer, return the empty string.

Example 1:

Input: 
words = ["w","wo","wor","worl", "world"]
Output: "world"
Explanation: 
The word "world" can be built one character at a time by "w", "wo", "wor", and "worl".

Example 2:

Input: 
words = ["a", "banana", "app", "appl", "ap", "apply", "apple"]
Output: "apple"
Explanation: 
Both "apply" and "apple" can be built from other words in the dictionary. However, "apple" is lexicographically smaller than "apply".

Note:

All the strings in the input will only contain lowercase letters.
The length of words will be in the range [1, 1000].
The length of words[i] will be in the range [1, 30].

class Solution(object):
    def longestWord(self, words):
        """
        :type words: List[str]
        :rtype: str
        """
        ans=""
        wordset=set(words)
        for w in words:
            if len(w)>len(ans) or (len(w)==len(ans) and w<ans):
                if all(w[:k] in wordset for k in range(1,len(w))):
                    ans=w
        return ans

转载于:https://www.cnblogs.com/chiyeung/p/10155861.html