qiaoxu123
11/26/2018 - 11:54 PM

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 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.

test.cpp
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//使用哈希法，用数组提前记录所有值，然后再进行遍历
class Solution {
public:
    int numJewelsInStones(string J, string S) {
        int array[100] = {0};
        int temp = 0;
        for(int i = 0;i < S.length();i++){
            array[S[i] - 65]++;
        }
        for(int i = 0;i < J.length();i++){
            temp += array[J[i] - 65];
        }
        
        return temp;
    }
};