771- Jewels and Stones[C++]

题目：

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.

[C++]

class Solution {
public:
int numJewelsInStones(string J, string S) {
int count=0;
for(int i=0;i<S.length();i++)
{
for(int j=0;j<J.length();j++)
{
if(S[i]==J[j])
count++;
}
}
return count;
}
};