[LeetCode] Jewels and Stones

You're given strings jewels representing the types of stones that are jewels, and stones representing the stones you have. Each character in stones is a type of stone you have. You want to know how many of the stones you have are also jewels.

Letters are case sensitive, so "a" is considered a different type of stone from "A".

 

Example 1:

Input: jewels = "aA", stones = "aAAbbbb" Output: 3

Example 2:

Input: jewels = "z", stones = "ZZ" Output: 0

 

Constraints:

• 1 <= jewels.length, stones.length <= 50
• jewels and stones consist of only English letters.
• All the characters of jewels are unique.

 

원석찾기
보석의 각 알파벳은 고유한 것으로 이루어져있고 대소문자를 구분한다.
돌 문자열 중에 보석에 해당하는 것이 있다면 count가 올라가서 이를 합한 결과를 반환

 

class Solution {
    public int numJewelsInStones(String jewels, String stones) {
        int num = 0;
		for (int i = 0 ; i < stones.length(); i ++) {
			if(jewels.indexOf(stones.charAt(i)) != -1) {
				num++;
			}
		}
		return num;
    }
}