771. Jewels and Stones

Problem:

You're given strings J representing the types of stones that are jewels, and S representing the stones you have.  Each character in Sis 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.

Analysis:

skip

Soluiton:

1 2 3 4 5 6 7 8 9 10 11 12 13 14

class Solution { public int numJewelsInStones(String J, String S) { Set<Character> set = new HashSet<>(); for(char c: J.toCharArray()) { set.add(c); } int res = 0; for (char c: S.toCharArray()) { if (set.contains(c)) res++; } return res; } }