public static IList <int> GetNumberOfTreesForSlopes(
GridPoint startPoint,
IList <Tuple <int, int> > slopes,
SlopeMap slopeMap)
{
var result = new List <int>();
foreach (var slope in slopes)
{
int numberOfTreesForSlope = GetNumberOfTreesForSlope(startPoint, slope.Item1, slope.Item2, slopeMap);
result.Add(numberOfTreesForSlope);
}
return(result);
}
public static int GetNumberOfTreesForSlope(
GridPoint startPoint,
int slopeX,
int slopeY,
SlopeMap slopeMap)
{
GridPoint currentPosition = startPoint;
int numberOfTrees = 0;
while (currentPosition.Y < slopeMap.Height)
{
currentPosition = slopeMap.NormalizeGridPointX(currentPosition);
var type = slopeMap.GridCellTypes[currentPosition];
if (CellType.Tree.Equals(type))
{
numberOfTrees++;
}
currentPosition = currentPosition.MoveRight(slopeX).MoveUp(slopeY);
}
return(numberOfTrees);
}
public static SlopeMap ParseSlopeMap(IList <string> inputLines)
{
var height = inputLines.Count;
var width = inputLines.Count > 0 ? inputLines[0].Length : 0;
var gridCellTypes = new Dictionary <GridPoint, CellType>();
int y = 0;
foreach (var inputLine in inputLines)
{
int x = 0;
foreach (var pointDefinition in inputLine)
{
CellType type = CellType.Empty;
if (pointDefinition == '.')
{
type = CellType.Empty;
}
else if (pointDefinition == '#')
{
type = CellType.Tree;
}
else
{
throw new Exception($"Unrecognized slope character: {pointDefinition}");
}
GridPoint point = new GridPoint(x, y);
gridCellTypes.Add(point, type);
x++;
}
y++;
}
var result = new SlopeMap(width, height, gridCellTypes);
return(result);
}