Jewels and Stones
Real-world version: Refundable DropsThe statement here is our own: the same inputs, outputs and technique.
A bottle-return depot stamps every container it accepts with a single letter code. The string refundable lists the codes the depot pays a deposit on, one letter per code, and no code appears in that list twice.
A customer empties a sack into the chute. The string dropped gives the code stamped on each container that went in, one letter per container, in the order they fell.
Codes are letters and the depot's stamping machine uses both cases, so 'd' and 'D' are two different codes and a deposit on one says nothing about the other.
Return how many of the dropped containers earn a deposit. A code that the depot pays on may of course turn up on several containers, and each of them earns its own deposit.
Examples
Example 1
- Input
- refundable = "aA", dropped = "aAAbb"
- Output
- 3
Both cases of a are paid on. Three of the five containers carry one of them, and the two b containers carry a code the depot does not pay on.
Example 2
- Input
- refundable = "z", dropped = "ZZZ"
- Output
- 0
The depot pays on lowercase z, and all three containers carry the uppercase code, which is a different code.
Example 3
- Input
- refundable = "A", dropped = "bAcAb"
- Output
- 2
Two of the five containers are stamped A, and each of those earns its own deposit.
Example 4
- Input
- refundable = "ABCDEFGHIJKLMNOPQRSTUVWXYZ", dropped = "abcdefghijklmnopqrstuvwxyz"
- Output
- 0
Every capital letter is paid on and every container carries a small letter, so nothing in the sack matches.
Constraints
- 1 <= refundable.length, dropped.length <= 50
- refundable and dropped consist of English letters only.
- All the characters of refundable are unique.
The signature
The editor starts with this. It matches the parent problem's shape, so a solution that works here works on a standard judge unchanged.
def num_jewels_in_stones(refundable: str, dropped: str) -> int:public int numJewelsInStones(String refundable, String dropped)Checking your plan…
How this problem was checked
- Passed: Reference solution run against 13 test cases: 13 passed
- Passed: 4 worked examples confirmed by running the code
- Passed: 0 eight-word sequences shared with the parent problem's text
- Passed: Agrees with an independent brute-force solution on random inputs
- Passed: Test set shown to catch deliberately broken solutions
- Passed: Reviewed by a separate quality pass
- Passed: Function arity matches the parent problem's