LeetCode-Solution

Description

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

The letters in 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 will consist of letters and have length at most 50. The characters in J are distinct.

思路

从S字符串中寻找存在于J字符串中的字符，需要得出符合条件的字符的数量。二次循环即可。

Java

public class Solution {
    public int numJewelsInStones(String J, String S) {
        int sum = 0;
        for (char c : S.toCharArray()) {
            if (J.indexOf(c) != -1) {
                sum++;
            }
        }
        return sum;
    }
}