1604 - Alert Using Same Key-Card Three or More Times in a One Hour Period.

Medium

LeetCode company workers use key-cards to unlock office doors. Each time a worker uses their key-card, the security system saves the worker's name and the time when it was used. The system emits an alert if any worker uses the key-card three or more times in a one-hour period.

You are given a list of strings keyName and keyTime where [keyName[i], keyTime[i]] corresponds to a person's name and the time when their key-card was used in a single day.

Access times are given in the 24-hour time format "HH:MM" , such as "23:51" and "09:49".

Return a list of unique worker names who received an alert for frequent keycard use. Sort the names in ascending order alphabetically.

Notice that "10:00" - "11:00" is considered to be within a one-hour period, while "22:51" - "23:52" is not considered to be within a one-hour period.

Example 1:

Input: keyName = "daniel","daniel","daniel","luis","luis","luis","luis", keyTime = "10:00","10:40","11:00","09:00","11:00","13:00","15:00"

Output: "daniel"

Explanation: "daniel" used the keycard 3 times in a one-hour period ("10:00","10:40", "11:00").

Example 2:

Input: keyName = "alice","alice","alice","bob","bob","bob","bob", keyTime = "12:01","12:00","18:00","21:00","21:20","21:30","23:00"

Output: "bob"

Explanation: "bob" used the keycard 3 times in a one-hour period ("21:00","21:20", "21:30").

Constraints:

• <code>1 <= keyName.length, keyTime.length <= 10⁵</code>

• keyName.length == keyTime.length

• keyTime[i] is in the format "HH:MM".

• [keyName[i], keyTime[i]] is unique.

• 1 <= keyName[i].length <= 10

• keyName[i] contains only lowercase English letters.