2025-08-13 18:05

Status: child

Tags: strings leetcode leetcode-easy Leetcode

Jewels and Stones

Code

class Solution(object):
    def numJewelsInStones(self, jewels, stones):
        """
        :type jewels: str
        :type stones: str
        :rtype: int
        """
        
        jewels_set = set(jewels)
        return sum(s in jewels_set for s in stones)

References

1. Essentially what we want to do is convert jewels into a set for O(1) look-ups
2. Then compare each element in stones to each element in the jewels set and return the sum for matching elements

Complexity

Time: O(n) Space: O(1) since alphabet size is fixed