[LeetCode]Jewels and Stones

题目描述：

LeetCode 771. Jewels and Stones

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.

题目大意：

给定字符串J和S，求S中在J中出现的字符总数。

解题思路：

蛮力法（Brute Force）

Python代码：

class Solution(object):
    def numJewelsInStones(self, J, S):
        """
        :type J: str
        :type S: str
        :rtype: int
        """
        return sum(s in J for s in S)