#2933

High-Access Employees

specialist · 920 · lc medium +32 · verified · 47.3% accepted · 226 likes · top 32%

Description

A 2D string array access_times records employee system accesses. Each entry access_times[i] = [name, time] gives an employee name and a 4-digit 24-hour time string. All entries are from the same day.

An employee is high-access when at least three of their access times fall within a single one-hour window (exclusive: times exactly one hour apart do not share a window; accesses do not wrap around midnight).

Return the names of high-access employees in any order.

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"].

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