public override ulong Part2(string input)
{
var traversals = new List <(int x, int y)>
{
(1, 1),
(3, 1),
(5, 1),
(7, 1),
(1, 2)
};
var map = new LoopingMap(input);
var result = traversals
.Select((slopes, y) =>
{
var treesCutDown = TraverseMap(map, slopes.x, slopes.y);
return(treesCutDown);
})
.Aggregate(1Lu, (acc, current) =>
{
var cast = (ulong)current;
return(acc * (cast));
});
return(result);
}
public void GetPosition_ReturnsCorrectInformation(int x, int y, PositionInformation expected)
{
var input = @"..##.......
#...#...#..
.#....#..#.
..#.#...#.#
.#...##..#.
..#.##.....
.#.#.#....#
.#........#
#.##...#...
#...##....#
.#..#...#.#";
var map = new LoopingMap(input);
var actual = map.GetPosition(x, y);
Assert.Equal(expected, actual);
}
public int TraverseMap(LoopingMap map, int xSlope, int ySlope)
{
var x = 0;
var y = 0;
var cutdownTrees = 0;
do
{
y += ySlope;
x += xSlope;
var currentTile = map.GetPosition(x, y);
if (currentTile == PositionInformation.Tree)
{
cutdownTrees++;
}
}while (y < map.Height - 1);
return(cutdownTrees);
}
public override ulong Part1(string input)
{
var map = new LoopingMap(input);
return((ulong)TraverseMap(map, 3, 1));
}
