# GeetCode Hub

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").
```

Example 3:

```Input: keyName = ["john","john","john"], keyTime = ["23:58","23:59","00:01"]
Output: []
```

Example 4:

```Input: keyName = ["leslie","leslie","leslie","clare","clare","clare","clare"], keyTime = ["13:00","13:20","14:00","18:00","18:51","19:30","19:49"]
Output: ["clare","leslie"]
```

Constraints:

• `1 <= keyName.length, keyTime.length <= 105`
• `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.`

class Solution { public List<String> alertNames(String[] keyName, String[] keyTime) { } }