private static void ExecutePart1(IEnumerable <string> map)
{
var slope = new Slope(3, 1);
var numberOfTrees = TraverseSlope(map, slope);
Console.WriteLine($"Part1 - Number of trees: {numberOfTrees}");
}
static void Main(string[] args)
{
var text = System.IO.File.ReadAllLines("input.txt");
var slope = new Slope {
Down = 1, Right = 3
};
var terrain = new Terrain();
terrain.Land = new List <bool> [text.LongLength];
var currentPosition = new Position();
//parse the terrain
for (var i = 0; i < text.Length; i++)
{
var currentTerrain = new List <bool>();
foreach (char c in text[i])
{
currentTerrain.Add(c == '#');
}
terrain.Land[i] = currentTerrain;
}
Part1(slope, terrain, currentPosition);
var slope1Position = new Position();
var slope1 = Part2(slope, terrain, slope1Position);
var slope2Position = new Position();
slope = new Slope {
Down = 1, Right = 1
};
var slope2 = Part2(slope, terrain, slope2Position);
var slope3Position = new Position();
slope = new Slope {
Down = 1, Right = 5
};
var slope3 = Part2(slope, terrain, slope3Position);
var slope4Position = new Position();
slope = new Slope {
Down = 1, Right = 7
};
var slope4 = Part2(slope, terrain, slope4Position);
var slope5Position = new Position();
slope = new Slope {
Down = 2, Right = 1
};
var slope5 = Part2(slope, terrain, slope5Position);
Console.WriteLine(slope1 * slope2 * slope3 * slope4 * slope5);
}
public static int CountTrees(Slope slope, Size vector)
{
Point pos = new Point(0, 0);
int numTrees = 0;
while (pos.Y < slope.Height)
{
if (slope.GetChar(pos) == '#')
{
numTrees++;
}
pos += vector;
}
return(numTrees);
}
public static int TraverseSlope(IEnumerable <string> map, Slope slope)
{
var xPos = 0;
for (int i = 0; i < map.Count(); i += slope.StepsDown)
{
var current = map.ElementAt(i);
var currentChar = current.ToCharArray()[xPos % current.Length];
if (currentChar == '#')
{
slope.AddTree();
}
xPos += slope.StepsRight;
}
return(slope.NumberOfTrees);
}
public List <long> FindCollisions(IEnumerable <Pattern> patterns, Slope slope)
{
string tree = "#";
var hits = (from p in patterns select(long) 0).ToList();
for (int y = 0, x = 0; y < patterns.Count(); y += slope.Y, x += slope.X)
{
var p = patterns.ElementAt(y).Row;
if (p.Substring(x % p.Length, 1) == tree)
{
hits[y]++;
}
}
return(hits);
}
static void Main(string[] args)
{
List <string> inputList = (args.Count() > 0) ? InputLoader.GetInputAsList(args[0]) : InputLoader.GetInputAsList("input.txt");
var slope = new Slope(inputList)
{
PositionX = 0, PositionY = 0, MovementRight = 3, MovementBottom = 1
};
slope.Start();
Console.WriteLine($"Trees encountered in part 1: {slope.TreesEncountered}");
// right 3, below 1
var slope31 = slope.TreesEncountered;
// right 1, below 1
slope.PositionX = slope.PositionY = 0;
slope.MovementRight = slope.MovementBottom = 1;
slope.Start();
var slope11 = slope.TreesEncountered;
// right 5, below 1
slope.PositionX = slope.PositionY = 0;
slope.MovementRight = 5;
slope.MovementBottom = 1;
slope.Start();
var slope51 = slope.TreesEncountered;
// right 7, below 1
slope.PositionX = slope.PositionY = 0;
slope.MovementRight = 7;
slope.MovementBottom = 1;
slope.Start();
var slope71 = slope.TreesEncountered;
// right 1, below 2
slope.PositionX = slope.PositionY = 0;
slope.MovementRight = 1;
slope.MovementBottom = 2;
slope.Start();
var slope12 = slope.TreesEncountered;
// part 2
Console.WriteLine($"Number for part 2: {slope11*slope31*slope51*slope71*slope12}");
Console.ReadLine();
}
private static void Part1(Slope slope, Terrain terrain, Position currentPosition)
{
for (long i = 0; i < terrain.Land.Length; i = i + slope.Down)
{
var row = terrain.Land[i];
int xPosition = currentPosition.x;
if (currentPosition.x > row.Count)
{
xPosition = xPosition % row.Count;
}
if (row[xPosition])
{
currentPosition.TreeCount += 1;
}
currentPosition.x = currentPosition.x + slope.Right;
currentPosition.y = currentPosition.y + slope.Down;
}
Console.WriteLine("Part 1 " + currentPosition.TreeCount);
}
private static long Part2(Slope slope, Terrain terrain, Position currentPosition)
{
//follow the tree down
for (long i = 0; i < terrain.Land.Length; i = i + slope.Down)
{
var row = terrain.Land[i];
int xPosition = currentPosition.x;
if (currentPosition.x >= row.Count)
{
xPosition = xPosition % row.Count;
}
if (row[xPosition])
{
currentPosition.TreeCount += 1;
}
currentPosition.x = currentPosition.x + slope.Right;
currentPosition.y = currentPosition.y + slope.Down;
}
Console.WriteLine("Part 2 " + currentPosition.TreeCount);
return(currentPosition.TreeCount);
}
static void Main(string[] args)
{
int numTrees = 0;
long product = 0;
Performance.TimeRun("Both stars", () => {
var slope = new Slope(TextFile.ReadStringList("input.txt"));
numTrees = CountTrees(slope, new Size(3, 1));
List <Size> vectors = new List <Size>()
{
new Size(1, 1),
new Size(5, 1),
new Size(7, 1),
new Size(1, 2),
};
product = numTrees;
for (int i = 0; i < vectors.Count; i++)
{
product *= CountTrees(slope, vectors[i]);
}
});
Console.WriteLine($"Crashed into {numTrees} trees");
Console.WriteLine($"Product is {product}");
}
