public static int GetDay03Part02Answer()
{
// --- Part Two ---
// Time to check the rest of the slopes -you need to minimize the probability of a sudden arboreal stop, after all.
// Determine the number of trees you would encounter if, for each of the following slopes, you start at the top - left corner and traverse the map all the way to the bottom:
// Right 1, down 1.
// Right 3, down 1. (This is the slope you already checked.)
// Right 5, down 1.
// Right 7, down 1.
// Right 1, down 2.
// In the above example, these slopes would find 2, 7, 3, 4, and 2 tree(s) respectively; multiplied together, these produce the answer 336.
// What do you get if you multiply together the number of trees encountered on each of the listed slopes ?
// Answer: 1206576000
var slopeMap = GetDay03Input();
var startPoint = new GridPoint(0, 0);
var slopes = new List <Tuple <int, int> >()
{
new Tuple <int, int>(1, 1),
new Tuple <int, int>(3, 1),
new Tuple <int, int>(5, 1),
new Tuple <int, int>(7, 1),
new Tuple <int, int>(1, 2)
};
var slopeResults = SlopeMapHelper.GetNumberOfTreesForSlopes(startPoint, slopes, slopeMap);
var result = SlopeMapHelper.GetProductOfSlopeResults(slopeResults);
return(result);
}
private static SlopeMap GetDay03Input()
{
var inputLines = new List <string>();
string filePath = Path.Combine(Directory.GetCurrentDirectory(), "InputData", FILE_NAME);
if (!File.Exists(filePath))
{
throw new Exception($"Cannot locate file {filePath}");
}
using (StreamReader sr = new StreamReader(filePath))
{
while (sr.Peek() >= 0)
{
string?currentLine = sr.ReadLine();
if (currentLine != null)
{
inputLines.Add(currentLine);
}
}
}
var result = SlopeMapHelper.ParseSlopeMap(inputLines);
return(result);
}
public static int GetDay03Part01Answer()
{
// ---Day 3: Toboggan Trajectory ---
// With the toboggan login problems resolved, you set off toward the airport. While travel by toboggan might be easy, it's certainly not safe: there's very minimal steering and the area is covered in trees.You'll need to see which angles will take you near the fewest trees.
// Due to the local geology, trees in this area only grow on exact integer coordinates in a grid. You make a map(your puzzle input) of the open squares(.) and trees(#) you can see. For example:
// ..##.......
// #...#...#..
// .#....#..#.
// ..#.#...#.#
// .#...##..#.
// ..#.##.....
// .#.#.#....#
// .#........#
// #.##...#...
// #...##....#
// .#..#...#.#
// These aren't the only trees, though; due to something you read about once involving arboreal genetics and biome stability, the same pattern repeats to the right many times:..##.........##.........##.........##.........##.........##....... --->
// #...#...#..#...#...#..#...#...#..#...#...#..#...#...#..#...#...#..
// .#....#..#..#....#..#..#....#..#..#....#..#..#....#..#..#....#..#.
// ..#.#...#.#..#.#...#.#..#.#...#.#..#.#...#.#..#.#...#.#..#.#...#.#
// .#...##..#..#...##..#..#...##..#..#...##..#..#...##..#..#...##..#.
// ..#.##.......#.##.......#.##.......#.##.......#.##.......#.##..... --->
// .#.#.#....#.#.#.#....#.#.#.#....#.#.#.#....#.#.#.#....#.#.#.#....#
// .#........#.#........#.#........#.#........#.#........#.#........#
// #.##...#...#.##...#...#.##...#...#.##...#...#.##...#...#.##...#...
// #...##....##...##....##...##....##...##....##...##....##...##....#
// .#..#...#.#.#..#...#.#.#..#...#.#.#..#...#.#.#..#...#.#.#..#...#.# --->
// You start on the open square(.) in the top-left corner and need to reach the bottom(below the bottom - most row on your map).
// The toboggan can only follow a few specific slopes(you opted for a cheaper model that prefers rational numbers) ; start by counting all the trees you would encounter for the slope right 3, down 1:
// From your starting position at the top - left, check the position that is right 3 and down 1.Then, check the position that is right 3 and down 1 from there, and so on until you go past the bottom of the map.
// The locations you'd check in the above example are marked here with O where there was an open square and X where there was a tree:..##.........##.........##.........##.........##.........##....... --->
// #..O#...#..#...#...#..#...#...#..#...#...#..#...#...#..#...#...#..
// .#....X..#..#....#..#..#....#..#..#....#..#..#....#..#..#....#..#.
// ..#.#...#O#..#.#...#.#..#.#...#.#..#.#...#.#..#.#...#.#..#.#...#.#
// .#...##..#..X...##..#..#...##..#..#...##..#..#...##..#..#...##..#.
// ..#.##.......#.X#.......#.##.......#.##.......#.##.......#.##..... --->
// .#.#.#....#.#.#.#.O..#.#.#.#....#.#.#.#....#.#.#.#....#.#.#.#....#
// .#........#.#........X.#........#.#........#.#........#.#........#
// #.##...#...#.##...#...#.X#...#...#.##...#...#.##...#...#.##...#...
// #...##....##...##....##...#X....##...##....##...##....##...##....#
// .#..#...#.#.#..#...#.#.#..#...X.#.#..#...#.#.#..#...#.#.#..#...#.# --->
// In this example, traversing the map using this slope would cause you to encounter 7 trees.
// Starting at the top-left corner of your map and following a slope of right 3 and down 1, how many trees would you encounter?
// Answer: 171
var slopeMap = GetDay03Input();
var startPoint = new GridPoint(0, 0);
int slopeX = 3;
int slopeY = 1;
var result = SlopeMapHelper.GetNumberOfTreesForSlope(startPoint, slopeX, slopeY, slopeMap);
return(result);
}