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

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.

int numJewelsInStones(char* J, char* S) {
    int a[256]={0};
    int i,j,k,sum=0;
    int len1=strlen(S);
    for(i=0;i<len1;i++)
        a[S[i]]++;
    int len2=strlen(J);
    for(i=0;i<len2;i++)
        sum+=a[J[i]];
    return sum;
}