## Algorithm

Problem Name: 771. 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.

## Code Examples

### #1 Code Example with C++ Programming

```Code - C++ Programming```

``````
class Solution {
public:
int numJewelsInStones(string J, string S) {
int count = 0;
unordered_sets;
for(char c: J) s.insert(c);
for(char c: S) if(s.count(c)) count++;
return count;
}
};
``````
Copy The Code &

Input

cmd
jewels = "aA", stones = "aAAbbbb"

Output

cmd
3

### #2 Code Example with Java Programming

```Code - Java Programming```

``````
class Solution {
public int numJewelsInStones(String J, String S) {
Set set = new HashSet<>();
for (char c : J.toCharArray()) {
}
int count = 0;
for (char c : S.toCharArray()) {
if (set.contains(c)) {
count++;
}
}
return count;
}
}
``````
Copy The Code &

Input

cmd
jewels = "aA", stones = "aAAbbbb"

Output

cmd
3

### #3 Code Example with Javascript Programming

```Code - Javascript Programming```

``````
const numJewelsInStones = function(J, S) {
if(J == null || J === '' || S == null || S === '') return 0
const m = new Set(J)
let res = 0
for(let e of S) {
if(m.has(e)) res++
}
return res
};
``````
Copy The Code &

Input

cmd
jewels = "z", stones = "ZZ"

### #4 Code Example with Python Programming

```Code - Python Programming```

``````
class Solution:
def numJewelsInStones(self, J, S):
sj = set(J)
return sum(s in sj for s in S)
``````
Copy The Code &

Input

cmd
jewels = "z", stones = "ZZ"

### #5 Code Example with C# Programming

```Code - C# Programming```

``````
using System.Collections.Generic;

namespace LeetCode
{
public class _0771_JewelsAndStones
{
public int NumJewelsInStones(string J, string S)
{
var map = new Dictionary();
foreach (var ch in J)

int result = 0;
foreach (var ch in S)
if (map.ContainsKey(ch)) result++;

return result;
}
}
}
``````
Copy The Code &

Input

cmd
jewels = "aA", stones = "aAAbbbb"

Output

cmd
3