Skip to main content

© 2026 CareerVerse. All rights reserved.

Pricing
Privacy
Terms
Refunds
Contact

Locker Registry Membership Log — Coding Problem — CareerVerse

Locker Registry Membership Log

EasyDesignHash-SetMembershipData-Structure5 hidden tests

A locker room tracks which locker ids are currently registered as in use. Starting from an empty registry, it processes q operations, each one of:

ADD x — register locker id x. If it is already registered, nothing changes.
REMOVE x — unregister locker id x. If it is not registered, nothing changes.
HAS x — report whether locker id x is currently registered.

Input format

Line 1: an integer q. Next q lines: one operation each.

Output format

For every HAS operation, in order, print 1 if the id is currently registered, otherwise 0.

Constraints

1 <= q <= 40
0 <= x <= 1000000

Examples

Example 1

Input

5
ADD 3
HAS 3
REMOVE 3
HAS 3
ADD 3

Expected

1
0

Explanation

After ADD 3, HAS 3 prints 1. After REMOVE 3, HAS 3 prints 0.

Example 2

Input

4
HAS 7
ADD 7
ADD 7
HAS 7

Expected

0
1

Explanation

Initially 7 is absent so HAS 7 prints 0. After registering it (twice; the second is a no-op), HAS 7 prints 1.

Ready to solve this?

Sign in to open the editor, run your code against the sample tests, and submit against the full test suite.

Sign in to solve →