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  • [leetcode-771-Jewels and Stones]

    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.

    思路:

    用map统计,扫描一遍S即可。

    int numJewelsInStones(string J, string S)
    {
        int ret = 0;
        map<char,int>mp;
        for(auto ch : S)mp[ch]++;
        
        for(int i= 0;i<J.size();j++)
        {
            ret += mp[J[i]];
        }
        return ret;
    }
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  • 原文地址:https://www.cnblogs.com/hellowooorld/p/8372243.html
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