public override void PartOne(IInput input, IOutput output)
{
ImmutableHashSet <Point2d> clayPoints = input.ParseClayPoints();
var(_, yRange) = Point2d.FindSpaceOfPoints(clayPoints);
var before = output.File("before.txt");
var after = output.File("after.txt");
var scan = new Scan(clayPoints);
scan.Write(before);
output.AddImage("before.png", ImageWriter.Generate(scan.Map));
scan.Flow(Scan.WaterSpring);
scan.Write(after);
output.AddImage("after.png", ImageWriter.Generate(scan.Map));
var waterBlocks = scan.Map
.Where(i => i.Key.Y >= yRange.Min)
.Count(i => i.Value is CellType.FlowingWater or CellType.StillWater);
output.WriteProperty("Number of flowing and still blocks", waterBlocks);
}