README.md

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.

Example 1:

Input: words = ["cat","bt","hat","tree"], chars = "atach"
Output: 6
Explanation:
The strings that can be formed are "cat" and "hat" so the answer is 3 + 3 = 6.

Example 2:

Input: words = ["hello","world","leetcode"], chars = "welldonehoneyr"
Output: 10
Explanation:
The strings that can be formed are "hello" and "world" so the answer is 5 + 5 = 10.

Note:

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

Solutions (Python)

1. Solution

class Solution:
    def countCharacters(self, words: List[str], chars: str) -> int:
        ret = 0

        cnt = [0] * 26
        for ch in chars:
            cnt[ord(ch) - 97] += 1

        for word in words:
            cnt_copy = cnt[:]
            flag = True

            for ch in word:
                if not cnt_copy[ord(ch) - 97]:
                    flag = False
                    break
                cnt_copy[ord(ch) - 97] -= 1

            if flag:
                ret += len(word)

        return ret