匹配子序列的单词数

/*
 * Problem: Given a string `s` and an array of strings `words`, return the number of words[i] that are subsequences of `s`.
 * 
 * Approach: Using Java Streams to filter and count words that are subsequences of `s`.
 * We use a helper method to check if a word is a subsequence of `s`.
 */
import java.util.Arrays;

public class Solution {
    public long numMatchingSubseq(String s, String[] words) {
        return Arrays.stream(words)
                     .filter(word -> isSubsequence(word, s))
                     .count();
    }

    private boolean isSubsequence(String word, String s) {
        int i = 0, j = 0;
        while (i < word.length() && j < s.length()) {
            if (word.charAt(i) == s.charAt(j)) {
                i++;
            }
            j++;
        }
        return i == word.length();
    }
}