771 questions, gems and stones

I, entitled ¹

        J given string represents the type of gem stones, and S represents a string of stone you have. S Each character represents a type of stone you have, you want to know the stone you have in how many gems.
        J letters will not be repeated, J S and all the characters are letters. A case-sensitive, so "a" and "A" are different types of stones.
Example 1:

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

Example 2:

Input: J = "z", S = "ZZ"
Output: 0

note:

• J S and containing up to 50 letters.
• J The characters are not repeated.

Second, the idea

Third, the code

public class T0771 {

    public static void main(String[] args) {

        System.out.println( numJewelsInStones("aA","aAAbbbb" ) );       //3
        System.out.println( numJewelsInStones("z","ZZ" ) );             //0
    }

    public static int numJewelsInStones(String J, String S) {

        //最后的输出结果
        int result = 0;

        //将每一个判断项目转换为数组
        char[] item = J.toCharArray();

        //遍历字符串S输出结果
        for( int i = 0; i < S.length(); i++ ){

            for( char s : item ){

                if( s == S.charAt(i) )
                    result++;
            }
        }

        return result;
    }
}

---

1. Source: stay button (LeetCode)
   link: https: //leetcode-cn.com/problems/jewels-and-stones
   copyrighted by deduction from all networks. Commercial reprint please contact the authorized official, non-commercial reprint please indicate the source. ↩︎