# 文档更新说明

• 最后更新 2018年03月07日
• 首次更新 2018年03月07日

# 前言

使用Swift语言完成LetCode题目,简单题.

# 771. Jewels and Stones

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”.

## Example1

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


## Example2

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.