leetcode-1160-easy

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.
Constraints:

1 <= words.length <= 1000
1 <= words[i].length, chars.length <= 100
words[i] and chars consist of lowercase English letters.

思路一： 先把字符串转为 26 长度的数组，对每个词语分别计算就行

    public int countCharacters(String[] words, String chars) {
        int[] map = new int[26];
        for (char c : chars.toCharArray()) {
            map[c - 'a']++;
        }

        int ans = 0;
        for (String word : words) {
            boolean found = true;
            int[] clone = map.clone();
            for (char c : word.toCharArray()) {
                clone[c - 'a']--;
                if (clone[c - 'a'] < 0) {
                    found = false;
                    break;
                }
            }
            if (found) {
                ans += word.length();
            }
        }

        return ans;
    }