LeetCode-771 Jewels and Stones Solution with Java

1. Description:

Notes:

2. Examples:

3.Solutions:

Version 1: hashmap

 1  /**
 2      * Created by sheepcore on 2020-03-02
 3      * @param J
 4      * @param S
 5      * @return the numbers of jewels in stones
 6      */
 7     public int numJewelsInStones(String J, String S) {
 8         Map<Character, Integer> jewels = new HashMap<>();
 9         int check;
10         for (char c : J.toCharArray())
11             if (!jewels.containsKey(c))
12                 jewels.put(c, 0);
13 
14         for (char c: S.toCharArray())
15             if (jewels.containsKey(c))
16                 jewels.put(c, jewels.get(c) + 1);
17 
18         Collection<Integer> values = jewels.values();
19         int sum = 0;
20         for(int val : values) {
21             sum += val;
22         }
23         return sum;
24     }

Version 1: for-loop

1 public int numJewelsInStones(String J, String S) {
2         int num = 0;
3         for (int i = 0; i < S.length(); i++) {
4             if (J.contains(S.charAt(i) + ""))
5                 num++;
6         }
7         return num;
8     }