AdventOfCode23/Day6/RaceTimeParser.cs

using System.Text.RegularExpressions;

namespace Day6;

public partial class RaceTimeParser
{
    [GeneratedRegex(@"\d+")]
    private partial Regex NumberList();
    
    public IList<RaceStats> Parse(string inputFile)
    {
        using var reader = File.OpenText(inputFile);

        var timesLine = reader.ReadLine()!;
        var times = NumberList().Matches(timesLine.Substring("Time:".Length)).Cast<Match>().Select(x => long.Parse(x.Value)).ToList();
        var durationsLine = reader.ReadLine()!;
        var durations = NumberList().Matches(durationsLine.Substring("Distance:".Length)).Cast<Match>().Select(x => long.Parse(x.Value)).ToList();

        if (times.Count != durations.Count)
        {
            throw new Exception("Expecting the same number of times and distances");
        }

        return times.Zip(durations).Select(item => new RaceStats(item.First, item.Second)).ToList();
    }
}