329. Jewels and Stones
Easy
Membership Counting
Hashing
Problem
You are given strings jewels and stones. Every character in stones represents a stone you have, while every character in jewels represents a type of stone considered a jewel. Letters are case-sensitive. Return how many stones are jewels.
Examples
Example 1
Input: "aA", "aAAbbbb"
Output: 3
Example 2
Input: "z", "ZZ"
Output: 0
Example 3
Input: "abc", "aabbcc"
Output: 6
Constraints
� 1 <= jewels.length, stones.length <= 50
� jewels and stones consist of English letters.
� All characters in jewels are unique.
Hints
?? Store all jewel characters in a set.
?? Scan stones and count membership hits.
Expected Complexity
Time: O(jewels.length + stones.length)
Space: O(number of jewel types)
Follow-up
Can you solve it using a fixed lookup table instead of a hash set?
Practice Notes
Attempts: 0
Time spent: 0min
Hints used: 0
JavaScript
00:00
Loading...
Case 1
Case 2
Case 3
Input
"aA", "aAAbbbb"Expected
3