leetcode- 771. Jewels and Stones（宝石和石头）

自己动手做的leetcode第一题（被女朋友逼着做的。。。）

771. Jewels and Stones（宝石和石头）

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.

体验：

  零基础coding真是蛋疼啊，慌的要死。

 1. strings 代表什么类型？怎么取长度？操作

思路：从J【0】开始与J[J.size（）]里的元素分别对比，相同则sum+1,不同则跳过。

遇到问题：1. string类型的J和S, 如何取其中某个元素？（本题按照数组形式）

                  2. string类型J 和S 的长度如何得到？（是S.size()还是sizeof(S)??）

 

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