TopCoder problem "Iditarod" used in SRM 160 (Division I Level One)



Problem Statement

    The Iditarod is a dogsled race from Anchorage to Nome that takes many days. We want to take a list of the times when the competitors crossed the finish line and convert that into the average number of minutes to complete the race.

The race starts on day 1 at 8:00 AM. We are given a list of finish times as a String[], where each finish time is formatted as

  • hh:mm xM, DAY n
where hh is exactly 2 digits giving the hour, mm is exactly 2 digits giving the minute, x is either 'A' or 'P', and n is a positive integer less than 100 with no leading zeros. So each string has exactly 15 or 16 characters (depending on whether n is less than 10).

Create a class Iditarod containing method avgMinutes that is given a String[], times, and that returns the average number of minutes taken by the competitors to complete the race. Round the returned value to the nearest minute, with .5 rounding up.

 

Definition

    
Class:Iditarod
Method:avgMinutes
Parameters:String[]
Returns:int
Method signature:int avgMinutes(String[] times)
(be sure your method is public)
    
 

Notes

-"12:00 AM, DAY d" refers to midnight between DAY d-1 and DAY d
-"12:00 PM, DAY d" refers to noon on DAY d
 

Constraints

-times contains between 1 and 50 elements inclusive
-each element of times is formatted as specified above, with hh between 01 and 12 inclusive, mm between 00 and 59 inclusive, and d between 1 and 99 inclusive
-each element of times represents a time later than the start of the race
 

Examples

0)
    
{"12:00 PM, DAY 1","12:01 PM, DAY 1"}
Returns: 241
From 8:00 AM to noon is 4 hours, so we have 4 hours for one competitor, and 4 hours, 1 minute for the other. These two values average to 240.5 minutes which is rounded up.
1)
    
{"12:00 AM, DAY 2"}
Returns: 960
The one competitor finished in 16 hours, just at the start of DAY 2.
2)
    
{"02:00 PM, DAY 19","02:00 PM, DAY 20", "01:58 PM, DAY 20"}
Returns: 27239
26280 minutes, 27720 minutes, 27718 minutes average to 27239.333 which rounds down.

Problem url:

http://www.topcoder.com/stat?c=problem_statement&pm=1647

Problem stats url:

http://www.topcoder.com/tc?module=ProblemDetail&rd=4605&pm=1647

Writer:

dgoodman

Testers:

lbackstrom , brett1479

Problem categories:

String Parsing