给定字符串和（列表）单词，返回包含字符串的单词（最优算法）

Question

Let's say we have a list of unique words and a substring.

I am looking for an optimal algorithm, that returns words containing the substring.

The general application is: Given a database use search bar to filter the results.

A simple implementation in Python:

def search_bar(words, substring):
    ret = []
    for word in words:
        if substring in word:
            ret.append(word)
    return ret

words = ["abc", "bcd", "thon", "Python"]
substring = "on"

search_bar(words, substring)

this would return:

["thon", "Python"]

in time O(lenght_of_list * complexity_of_in) , where complexity_of_in depends in some way on the length of the substring and the length of individual words.

What I am asking is whether there is faster implementation. Given that we can preprocess the list into any structure we want.

Just redirection to the problem/answer would be amazing.

Note: It would be better if such structure doesn't take too long to add a new word. But primarily it doesn't have to be able to add anything, as the Python example doesn't.

Also, I am not sure about the tags with this question...

Answer 1

maybe use

word.find(substring) 

instead

substring in word

and as variant:

def search_bar(words, substring):
    return list(filter(lambda word: word.find(substring)!=-1, words))