771. Jewels and Stones

Question 771

https://leetcode.com/problems/jewels-and-stones/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.

Answer

class Solution:
    def numJewelsInStones(self, J, S):
        
        countnum = 0
        
        for stone in S:
            if stone in J:
                countnum += 1
                
        return countnum