Problem Brief

Authentication System 🐹

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Develop a session-based authentication system where each user session generates a new token with a specified time-to-live (TTL) expiration. The TTL expiration is calculated as the current time plus the time-to-live seconds. If a token is renewed, the TTL is extended to the time-to-live seconds after the time of the renewal.

There are three types of queries in this system:

"generate <token_id> <current_time>": Creates a new token with the given token_id and current_time.

"renew <token_id> <current_time>": Renews an unexpired token with the given token_id and current_time. If there is no unexpired token with the specified token_id, the request is ignored.

"count <current_time>": Returns the number of unexpired tokens at the given current_time.

Note: If a token expires at a specific time and any action is performed at that same time, the token's expiration occurs before any other actions are carried out.

Function Description

Complete the function getUnexpiredTokens in the editor below.

getUnexpiredTokens has the following parameter(s):

1. int time_to_live: the time to live for a token
2. String[] queries: the queries

Returns

int[]: the results from type-3 query in the same order it is given

1Example 1

Input

time_to_live = 5, queries = [["generate aaa 1"], ["renew aaa 2"], ["count 6"], ["generate bbb 7"], ["renew aaa 8"], ["renew bbb 10"], ["count 15"]]

Output

[1, 0]

Explanation

The output of the system is [1, 0]. At t = 6, the only unexpired token is "aaa". At t = 15, all tokens have expired, so the count of unexpired tokens is 0.

Constraints

Limits and guarantees your solution can rely on.

Unknwon for now