In this problem we are using 24-hour time. That is, the first second of each day is 00:00:00 and the last second of each day is 23:59:59.
You are visiting an online forum. Whenever there is a post that has been made strictly less than 24 hours ago, the forum displays a human-readable message stating when it was made. There are three types of messages:
-
few seconds ago, which means the post is made between 0 and 59 seconds ago, inclusive. -
X minutes ago, where X is an integer between 1 and 59, inclusive, which means the post is made between X minutes and X minutes 59 seconds ago, inclusive. -
X hours ago, where X is an integer between 1 and 23, inclusive, which means the post is made between X hours and X hours 59 minutes 59 seconds ago, inclusive.
You are given the string[]s exactPostTime and showPostTime, both with the same number of elements. For each valid index i you know the following information:
- Post i was made strictly less than 24 hours ago.
- The exact time of day when post i was made is exactPostTime[i].
- The human-readable string currently displayed by the forum software about post i is showPostTime[i].
Given all the information above, what is the current time?
Return the answer in the format "HH:MM:SS". If there are multiple solutions, return the one that comes first lexicographically. If the information given to you is self-contradictory and there is no solution, return "impossible" instead.
Class: ForumPostEasy
Method: GetCurrentTime
Parameters: `string[], string[]``
Returns: string
Method signature: string GetCurrentTime(string[] exactPostTime, string[] showPostTime)
(be sure your method is public)
- The lexicographically smaller of two equally-long strings is the one that has a character with a smaller ASCII value at the first index at which they differ.
- exactPostTime will contain between 0 and 50 elements, inclusive.
- Each element of exactPostTime will be formatted as HH:MM:SS where HH is a two-digit integer between 00 and 23, inclusive, and both MM and SS are two-digit integers between 00 and 59, inclusive.
- exactPostTime and showPostTime will contain same number of elements.
- Each element of showPostTime will have one of the formats described in problem statment.
1
{"12:12:12"}
{"few seconds ago"}
Returns: "12:12:12"
The current time is somewhere between 12:12:12 and 12:13:11, inclusive. The returned time is the lexicographically smallest one out of all these times.
2
{"23:23:23","23:23:23"}
{"59 minutes ago","59 minutes ago"}
Returns: "00:22:23"
Both posts were made on the previous day. The current time is a bit after midnight.
3
{"00:10:10","00:10:10"}
{"59 minutes ago","1 hours ago"}
Returns: "impossible"
Two posts made in the same second cannot have two different human-readable strings.
4
{"11:59:13","11:13:23","12:25:15"}
{"few seconds ago","46 minutes ago","23 hours ago"}
Returns: "11:59:23"
The post made at 12:25:15 was posted yesterday at that time of day.