Watch 10 video solutions for Number of Valid Clock Times, a easy level problem involving String, Enumeration. This walkthrough by NeetCode has 660,685 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
You are given a string of length 5 called time, representing the current time on a digital clock in the format "hh:mm". The earliest possible time is "00:00" and the latest possible time is "23:59".
In the string time, the digits represented by the ? symbol are unknown, and must be replaced with a digit from 0 to 9.
Return an integer answer, the number of valid clock times that can be created by replacing every ? with a digit from 0 to 9.
Example 1:
Input: time = "?5:00" Output: 2 Explanation: We can replace the ? with either a 0 or 1, producing "05:00" or "15:00". Note that we cannot replace it with a 2, since the time "25:00" is invalid. In total, we have two choices.
Example 2:
Input: time = "0?:0?" Output: 100 Explanation: Each ? can be replaced by any digit from 0 to 9, so we have 100 total choices.
Example 3:
Input: time = "??:??" Output: 1440 Explanation: There are 24 possible choices for the hours, and 60 possible choices for the minutes. In total, we have 24 * 60 = 1440 choices.
Constraints:
time is a valid string of length 5 in the format "hh:mm"."00" <= hh <= "23""00" <= mm <= "59"'?' and need to be replaced with digits from 0 to 9.