[leeccode]771. Jewels and Stones

J representing the types of stones that are jewels, and S representing the stones you have.  Each character in Sis a type of stone you have.  You want to know how many of the stones you have are also jewels.J are guaranteed distinct, and all characters in J and S are letters. Letters are case sensitive, so "a" is considered a different type of stone from "A".

Example 1:

Input: J = "aA", S = "aAAbbbb"
Output: 3

Example 2:

Input: J = "z", S = "ZZ"
Output: 0

Note:

S

•  and 

J

• The characters in 

J

solution:

public int numJewelsInStones(String j, String s) {
        int result = 0;
        Set<Character> jc = new HashSet<Character>();
        for (Character i : j.toCharArray()) {
            jc.add(i);
        }

        for (Character i : s.toCharArray()) {
            if (jc.contains(i)) {
                result++;
            }
        }
        return result;
    }