LeetCode-771 Jewels and Stones Solution with Java

1. Description:

Notes:

2. Examples: 

3.Solutions:

Version 1: hashmap

 /**
     * Created by sheepcore on 2020-03-02
     * @param J
     * @param S
     * @return the numbers of jewels in stones
     */
    public int numJewelsInStones(String J, String S) {
        Map<Character, Integer> jewels = new HashMap<>();
        int check;
        for (char c : J.toCharArray())
            if (!jewels.containsKey(c))
                jewels.put(c, 0);

        for (char c: S.toCharArray())
            if (jewels.containsKey(c))
                jewels.put(c, jewels.get(c) + 1);

        Collection<Integer> values = jewels.values();
        int sum = 0;
        for(int val : values) {
            sum += val;
        }
        return sum;
    }

Version 1:  for-loop

public int numJewelsInStones(String J, String S) {
        int num = 0;
        for (int i = 0; i < S.length(); i++) {
            if (J.contains(S.charAt(i) + ""))
                num++;
        }
        return num;
    }