1160. Find Words That Can Be Formed by Characters

You are given an array of strings words and a string chars.

A string is good if it can be formed by characters from chars (each character can only be used once).

Return the sum of lengths of all good strings in words.

1. 1 <= words.length <= 1000
2. 1 <= words[i].length, chars.length <= 100
3. All strings contain lowercase English letters only.

开一个计数数组count，统计chars里每个字符出现的次数，然后for一遍words，word出现的字符计数-1，看看是否有的字符的计数小于0了,小于0就作废，不小于0就加长度。

class Solution(object):
    def countCharacters(self, words, chars):
        """
        :type words: List[str]
        :type chars: str
        :rtype: int
        """
        count = [0] * 26
        ans = 0
        for c in chars:
            count[ord(c) - ord('a')] += 1
        for s in words:
            cp_count = [value for value in count]
            length = 0
            for c in s:
                if cp_count[ord(c) - ord('a')] > 0:
                    length += 1
                    cp_count[ord(c) - ord('a')] -= 1
                else:
                    length = 0
                    break
            ans += length
        return ans