Skip to content

Commit

Permalink
day 8 2024
Browse files Browse the repository at this point in the history
  • Loading branch information
@plucked
plucked committed Dec 15, 2024
1 parent b163bea commit 463dc27
Show file tree
Hide file tree
Showing 3 changed files with 264 additions and 0 deletions.
50 changes: 50 additions & 0 deletions AdventOfCode/Year2024/2024_08_input.txt
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,50 @@
.............C.7..................G..0...y........
..................7................C..............
....................................0......W....y.
.......................................D..W.......
..........u.......................................
..................................4.......D0...j..
.....................................D............
................O.....C................G..........
............F.....................C...............
......u..........F.................4.......y......
..........X..........5....4...........1...........
..........F...........5X...................3......
.............F.............................j.3....
.................u..............X.................
............................7.....................
..................................................
..........................5.....j2.........4......
....d.....................y...................j1..
..................................................
............................Y.e...................
.................d...X...............J...........e
.............d....................................
..............................Y..............1....
.........................................Y........
......................W......8..f...J.........3...
.......w.............J............................
...................................U.....f......e.
.................................Of....e....t...1.
.......g..........d......s........................
................G................f................
.....................................O............
...g........................T.....U...............
......................s..........T.............G..
................................s.......8.........
.....9........g...........o...U............E......
............g............................t....o...
...........................................6....E.
.....................s......x........6....E.......
..........w.9................x............t.......
...........9........w...........J.....6o..........
.............................................o....
..........S................U......................
.......S..2..........c........T.O....t............
.....2...S.....c...................T..............
..................x.......................8.......
....9.............................................
...wS.....................................6.......
................2........................8........
..................................................
.................x....c........................E..
143 changes: 143 additions & 0 deletions AdventOfCode/Year2024/AoC2024Day08.cs
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,143 @@
using System.Numerics;
using AdventOfCode.Utilities;
using BenchmarkDotNet.Attributes;

namespace AdventOfCode.Year2024;

public class AoC2024Day08
{
// input is negative when line is empty
private readonly char[,] map;

public AoC2024Day08(string? customInput = null)
{
var content = (customInput ?? EmbeddedInput.ReadAllText("Year2024/2024_08_input.txt"));
var lines = content.Split('\n', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
map = new char[lines.Length, lines[0].Length];
for (int i = 0; i < lines.Length; i++)
{
var line = lines[i];
for (int j = 0; j < line.Length; j++)
{
map[i, j] = line[j];
}
}
}

[Benchmark]
public long Solution1()
{
var antennasPerType = new Dictionary<char, List<(int x, int y)>>();
for (int x = 0; x < map.GetLength(0); x++)
{
for (int y = 0; y < map.GetLength(1); y++)
{
var antennaType = map[x, y];
if (antennaType == '.')
{
continue;
}

if (!antennasPerType.TryGetValue(antennaType, out var antennas))
{
antennas = new List<(int x, int y)>();
antennasPerType[antennaType] = antennas;
}

antennas.Add((x, y));
}
}

var antiNodes = new HashSet<(int x, int y)>();

foreach (var (_, coords) in antennasPerType)
{
foreach (var coordA in coords)
{
foreach (var coordB in coords)
{
if (coordA == coordB)
{
continue;
}

var diffX = coordA.x - coordB.x;
var diffY = coordA.y - coordB.y;
var antiNode = (x: coordA.x + diffX, y: coordA.y + diffY);


if (antiNode.x < 0 || antiNode.x >= map.GetLength(0) || antiNode.y < 0 ||
antiNode.y >= map.GetLength(1))
{
continue;
}

antiNodes.Add(antiNode);
}
}
}

return antiNodes.Count;
}

[Benchmark]
public long Solution2()
{
var antennasPerType = new Dictionary<char, List<(int x, int y)>>();
for (int x = 0; x < map.GetLength(0); x++)
{
for (int y = 0; y < map.GetLength(1); y++)
{
var antennaType = map[x, y];
if (antennaType == '.')
{
continue;
}

if (!antennasPerType.TryGetValue(antennaType, out var antennas))
{
antennas = new List<(int x, int y)>();
antennasPerType[antennaType] = antennas;
}

antennas.Add((x, y));
}
}

var antiNodes = new HashSet<(int x, int y)>();
foreach (var (_, coords) in antennasPerType)
{
if (coords.Count == 1)
{
continue;
}

foreach (var coordA in coords)
{
antiNodes.Add(coordA);
foreach (var coordB in coords)
{
if (coordA == coordB)
{
continue;
}

var diffX = coordA.x - coordB.x;
var diffY = coordA.y - coordB.y;

var antiNode = (x: coordA.x + diffX, y: coordA.y + diffY);

while (antiNode.x >= 0 && antiNode.x < map.GetLength(0) && antiNode.y >= 0 &&
antiNode.y < map.GetLength(1))
{
antiNodes.Add(antiNode);
antiNode = (x: antiNode.x + diffX, y: antiNode.y + diffY);
}
}
}

}

return antiNodes.Count;
}
}
71 changes: 71 additions & 0 deletions AdventOfCodeTests/Year2024/AoC2024Day08Tests.cs
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,71 @@
using AdventOfCode.Year2024;
using System;
using NUnit.Framework;

namespace AdventOfCodeTests.Year2024;

[TestFixture]
public class AoC2024Day08Tests {
[Test]
public void Solution1Examples()
{
string input = """
............
........0...
.....0......
.......0....
....0.......
......A.....
............
............
........A...
.........A..
............
............
""";

long expect = 14;

var instance = new AoC2024Day08(input);
Assert.That(instance.Solution1(), Is.EqualTo(expect));
}

[Test]
public void Solution1Test() {
var instance = new AoC2024Day08();
var result = instance.Solution1();
Assert.That(result, Is.EqualTo(222));
Console.WriteLine($"Result: {result}");
}

[Test]
public void Solution2Examples() {
string input = """
............
........0...
.....0......
.......0....
....0.......
......A.....
............
............
........A...
.........A..
............
............
""";

long expect = 34;

var instance = new AoC2024Day08(input);
Assert.That(instance.Solution2(), Is.EqualTo(expect));
}

[Test]
public void Solution2Test() {
var instance = new AoC2024Day08();
var result = instance.Solution2();
Assert.That(result, Is.EqualTo(884));
Console.WriteLine($"Result: {result}");
}
}

0 comments on commit 463dc27

Please sign in to comment.