# Jewels and Stones

## [Jewels and Stones](https://leetcode.com/problems/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**.

## Solutions

### 🐍 Python

```python
class Solution:
    # O(n^2) solution
    def numJewelsInStones(self, J: str, S: str) -> int:
        return len( [ j for j in S if j in J ] )
```