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Jewels and Stones - Hash Table - Easy - LeetCode - MiniTV

Jewels and Stones - Hash Table - Easy - LeetCode - मिनी टीवी

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.

public class Solution {
    public int NumJewelsInStones(string J, string S) {
        var set = new HashSet<char>();
        for(int i=0;i<J.Length;i++){
            set.Add(J[i]);
        }
        
        int count = 0;
        for(int i=0;i<S.Length;i++){
            if(set.Contains(S[i])){
                count++;
            }
        }
        
        return count;
    }
}

Time Complexity: O(n)

Space Complexity: O(n)