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:

 12 Input: J = "aA", S = "aAAbbbb" Output: 3 

Example 2:

 12 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.

Related Topics:Hash Table

## 解題邏輯與實作

 12345 class Solution: def numJewelsInStones(self, J, S): J = set(J) counter = [c for c in S if c in J] return len(counter) 

 123 class Solution: def numJewelsInStones(self, J, S): return(sum(map(J.count,S)))