1961 check if string is a prefix of array

This series is a new pit opened out of personal interest , Recently I saw my classmates brush LeetCode Algorithm problem , Just want to write those that can be one line Python The title of the code , Therefore, the efficiency of problem-solving methods in this column is not guaranteed , Only for pursuit “ The romance of one line ”.

subject

Answer key

Explain the subject briefly , Given a string s, And a list of strings words, solve s Whether it is words Prefix string （ namely words In front of k Whether or not one can form s）. The difficulty of this question is Easy.

Code

The train of thought of this question is relatively simple , Cumulative direct violence against words Before k Splices , See if there is a former k The splicing result of is equal to s, If there is such a k, The output true, Otherwise output false.

class Solution:
    def isPrefixString(self, s: str, words: List[str]) -> bool:
        return sum(map(lambda x: x == s, [''.join(words[:i+1]) for i in range(len(words))])) > 0

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