Inspired by this r/dailyprogrammer post, the task is too calculate which records to use in order to serve the most records without any of the records having overlapping time spans.

I accomplish this goal by sorting the list of records by their total days spanned, then by iterating over each element and adding it to a new list as long as that record does not overlap with any records already within the “optimized” list.

The source,

internal class Program {     private static void Main(string[] args)     {         var rentalRecords = RentalRecordLoader.Load("rentals.txt");         var result = RentalRecordOptimizer.CalculateMostEfficientRecords(rentalRecords);          Console.WriteLine($  "Total Records: {result.Count}");         result.ForEach(r => Console.WriteLine($  "{r.StartDay} : {r.EndDay}"));     } }  public class RentalRecord {     public int StartDay { get; set; }     public int EndDay { get; set; }      public RentalRecord(int startDay, int endDay)     {         StartDay = startDay;         EndDay = endDay;     }      public int TotalDays()     {         return EndDay - StartDay;     }      public bool Overlapping(RentalRecord rentalRecord)     {         return StartDay <= rentalRecord.EndDay &&             rentalRecord.StartDay <= EndDay;     } }  public abstract class RentalRecordLoader {     public static List<RentalRecord> Load(string path)     {         int recordCount;         int[] startDays;         int[] endDays;         using (var reader = new StreamReader(path))         {             recordCount = int.Parse(reader.ReadLine());             startDays = ConvertStringToIntArray(reader.ReadLine());             endDays = ConvertStringToIntArray(reader.ReadLine());         }          var rentalList = new List<RentalRecord>();         for (var i = 0; i < recordCount; i++)         {             rentalList.Add(new RentalRecord(startDays[i], endDays[i]));         }          return rentalList;     }      // Load() helper method     private static int[] ConvertStringToIntArray(         string value, string delimeter = " ")     {         return value.Trim().Split(delimeter)                 .Select(x => int.Parse(x))                 .ToArray();     } }  public abstract class RentalRecordOptimizer {     public static List<RentalRecord> CalculateMostEfficientRecords(         List<RentalRecord> rentals)     {         var efficientRentals = new List<RentalRecord>();         foreach (var rental in rentals.OrderBy(x => x.TotalDays()))         {             // Cant have any overlapping days.             // The car cant be in two places at once.             if (efficientRentals.Any(x => x.Overlapping(rental)))             {                 continue;             }             efficientRentals.Add(rental);         }         return efficientRentals;     } } 

The input used (stored in rentals.txt)

10 1 2 5 12 13 40 30 22 70 19 23 10 10 29 25 66 35 33 100 65 

And the output:

Total Records: 5 5 : 10 30 : 35 13 : 25 40 : 66 70 : 100 

Optimizations and better code design is obviously welcome, but I also had a specific question as well.

1. What would be the best way to handle incorrectly formatted data in
   rentals.txt? Just catch the exception in the Load function?