#2933

High-Access Employees

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Description

You are given a 2D 0-indexed array of strings, access_times, with size n. For each i where 0 <= i <= n - 1, access_times[i][0] represents the name of an employee, and access_times[i][1] represents the access time of that employee. All entries in access_times are within the same day.

The access time is represented as four digits using a 24-hour time format, for example, "0800" or "2250".

An employee is said to be high-access if he has accessed the system three or more times within a one-hour period.

Times with exactly one hour of difference are not considered part of the same one-hour period. For example, "0815" and "0915" are not part of the same one-hour period.

Access times at the start and end of the day are not counted within the same one-hour period. For example, "0005" and "2350" are not part of the same one-hour period.

Return a list that contains the names of high-access employees with any order you want.

Example 1:

Input: access_times = [["a","0549"],["b","0457"],["a","0532"],["a","0621"],["b","0540"]]

Output: ["a"]

Explanation: "a" has three access times in the one-hour period of [05:32, 06:31] which are 05:32, 05:49, and 06:21.

But "b" does not have more than two access times at all.

So the answer is ["a"].

Example 2:

Input: access_times = [["d","0002"],["c","0808"],["c","0829"],["e","0215"],["d","1508"],["d","1444"],["d","1410"],["c","0809"]]

Output: ["c","d"]

Explanation: "c" has three access times in the one-hour period of [08:08, 09:07] which are 08:08, 08:09, and 08:29.

"d" has also three access times in the one-hour period of [14:10, 15:09] which are 14:10, 14:44, and 15:08.

However, "e" has just one access time, so it can not be in the answer and the final answer is ["c","d"].

Example 3:

Input: access_times = [["cd","1025"],["ab","1025"],["cd","1046"],["cd","1055"],["ab","1124"],["ab","1120"]]

Output: ["ab","cd"]

Explanation: "ab" has three access times in the one-hour period of [10:25, 11:24] which are 10:25, 11:20, and 11:24.

"cd" has also three access times in the one-hour period of [10:25, 11:24] which are 10:25, 10:46, and 10:55.

So the answer is ["ab","cd"].

Solution