Day 1: Historian Hysteria
Megathread guidelines
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FAQ
- What is this?: Here is a post with a large amount of details: https://programming.dev/post/22323136
- Where do I participate?: https://adventofcode.com/
- Is there a leaderboard for the community?: We have a programming.dev leaderboard with the info on how to join in this post: https://programming.dev/post/6631465
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C#
public class Day01 : Solver
{
private ImmutableArray<int> left;
private ImmutableArray<int> right;
public void Presolve(string input)
{
var pairs = input.Trim().Split("\n").Select(line => Regex.Split(line, @"\s+"));
left = pairs.Select(item => int.Parse(item[0])).ToImmutableArray();
right = pairs.Select(item => int.Parse(item[1])).ToImmutableArray();
}
public string SolveFirst() => left.Sort().Zip(right.Sort()).Select((pair) => int.Abs(pair.First - pair.Second)).Sum().ToString();
public string SolveSecond() => left.Select((number) => number * right.Where(v => v == number).Count()).Sum().ToString();
}