【Leetcode】771. Jewels and Stones

class Solution1:
    """
    use dict
    """
    def numJewelsInStones(self, J, S) :
        count = 0
        set_J = set(J)
        for char in S:
            if char in set_J:
                count += 1
        return count

class Solution2:
    """
    use string.count
    """
    def numJewelsInStones(self, J, S) :
        return sum(map(S.count, J))

class Solution3:
    def numJewelsInStones(self, J, S) :
        return sum([i in J for i in S])