[LeetCode&Python] Problem 720. Longest Word in Dictionary
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