---
tags: data_structure_python
---

# Jewels and Stones <img src="https://img.shields.io/badge/-easy-brightgreen">

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.

# Solution

class Solution:
    def numJewelsInStones(self, J: str, S: str) -> int:
        jewels = set(J)
        count = 0    
        for stone in S:
            if stone in jewels:
                count += 1     
        return count