#
# Create by Hua on 5/19/22
#


"""
You are given a string array words and a string s, where words[i] and s comprise only of lowercase English letters.

Return the number of strings in words that are a prefix of s.

A prefix of a string is a substring that occurs at the beginning of the string. A substring is a contiguous sequence of characters within a string.



Example 1:

Input: words = ["a","b","c","ab","bc","abc"], s = "abc"
Output: 3
Explanation:
The strings in words which are a prefix of s = "abc" are:
"a", "ab", and "abc".
Thus the number of strings in words which are a prefix of s is 3.
Example 2:

Input: words = ["a","a"], s = "aa"
Output: 2
Explanation:
Both of the strings are a prefix of s.
Note that the same string can occur multiple times in words, and it should be counted each time.


Constraints:

1 <= words.length <= 1000
1 <= words[i].length, s.length <= 10
words[i] and s consist of lowercase English letters only.

"""


class Solution(object):
    def countPrefixes(self, words, s):
        """
        :type words: List[str]
        :type s: str
        :rtype: int

        thought: 2 pointers, check if short pointer will finish to the end
        05/19/2022 10:59	Accepted	84 ms	13.6 MB	python
        easy 5 min.

        """
        ret = 0
        m = len(s)
        for word in words:
            i = 0
            n = len(word)
            if n > m: continue
            while i< n:
                if word[i] != s[i]:
                    break
                i+=1
            if i == n:
                ret += 1
        return ret

