拼写单词

/**
 * This solution uses Java Streams to count the total length of words that can be formed.
 * We use a frequency map to count the characters in chars and then filter the words that can be formed.
 * The lengths of the filtered words are summed up to get the total length.
 */

import java.util.stream.IntStream;
import java.util.stream.Stream;

public class Solution {
    public int countCharacters(String[] words, String chars) {
        int[] charCount = new int[26];
        chars.chars().forEach(c -> charCount[c - 'a']++);
        return Stream.of(words)
                .filter(word -> canFormWord(word, charCount.clone()))
                .mapToInt(String::length)
                .sum();
    }

    private boolean canFormWord(String word, int[] charCount) {
        return word.chars().allMatch(c -> --charCount[c - 'a'] >= 0);
    }
}