advent_of_code_2024/Level2/Level2Solver.cs

namespace AoC24;

using AoC24.Common;
using AoCLevelInputProvider;
using Parsing;
using Parsing.Schema;

public class Level2Solver : LevelSolverBase
{
    public override int LevelNumber
    {
        get { return 2; }
    }

    protected override InputSchemaBuilder DefineInputSchema(InputSchemaBuilder schemaBuilder)
    {
        return schemaBuilder
                    .Repeat()
                        .Expect(InputType.Integer)
                    .EndRepetition();
    }

    private class MyDistanceChecker : DataStreamConstraintVerifier<int>.IIntegerDataStreamConstraint
    {
        public int Verify(int leftValue, int rightValue)
        {
            return Math.Abs(leftValue - rightValue);
        }
    }

    private class MyTrendChecker : DataStreamConstraintVerifier<int>.IIntegerDataStreamConstraint
    {
        public int Verify(int leftValue, int rightValue)
        {
            return (leftValue - rightValue) < 0 ? -1 : 1;
        }
    }

    public override string SolveFirstStar()
    {
        var data = this.GetData()
                       .AsListRows<int>();

        var distanceChecker = new MyDistanceChecker();

        var trendChecker = new MyTrendChecker();

        var verifier = new DataStreamConstraintVerifier<int>()
                        .WithDistanceChecker(distanceChecker)
                        .WithDistanceLimits(1, 3)
                        .WithTrendChecker(trendChecker);

        int numSafeReports = 0;

        foreach(var row in data)
        {
            if(verifier.OnData(row).Verify())
            {
                numSafeReports++;
            }
        }

        return numSafeReports.ToString();
    }

    public override string SolveSecondStar()
    {
        var data = this.GetData()
                       .AsListRows<int>();

        var distanceChecker = new MyDistanceChecker();

        var trendChecker = new MyTrendChecker();

        var verifier = new DataStreamConstraintVerifier<int>()
                        .WithDistanceChecker(distanceChecker)
                        .WithDistanceLimits(1, 3)
                        .WithTrendChecker(trendChecker)
                        .WithAllowedIgnores(1);

        int numSafeReports = 0;

        foreach(var row in data)
        {
            if(verifier.OnData(row).Verify())
            {
                numSafeReports++;
            }
        }

        return numSafeReports.ToString();
    }
}