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feat: solved day 10 part 1 and part 2

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Stevan Freeborn
2024-12-10 20:52:40 -06:00
parent ac95a20479
commit 0cb78ca2d1
6 changed files with 223 additions and 128 deletions
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10/HoofIt.Tests/TopoMapTests.cs
+51 -3
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@@ -13,6 +13,11 @@ public class TopoMapTests
"10456732",
];
private async Task<string[]> GetPuzzleInput()
{
return await File.ReadAllLinesAsync(Path.Combine(AppContext.BaseDirectory, "INPUT.txt"));
}
[Test]
public async Task From_WhenCalled_ItShouldReturnNewInstanceOfTopoMap()
{
@@ -22,7 +27,7 @@ public class TopoMapTests
}
[Test]
public async Task GetTrailHeadScores_WhenCalledWithExampleInput_ItShouldReturnExpectedValues()
public async Task GetTrailheadScores_WhenCalledWithExampleInput_ItShouldReturnExpectedValues()
{
var expectedValues = new List<int>()
{
@@ -37,8 +42,51 @@ public class TopoMapTests
5,
};
var result = TopoMap.From(_exampleInput).GetTrailHeadScores();
var result = TopoMap.From(_exampleInput).GetTrailheadScores();
await Assert.That(result).IsEqualTo(36);
await Assert.That(result).IsEquivalentTo(expectedValues);
await Assert.That(result.Sum()).IsEqualTo(36);
}
[Test]
public async Task PartOne_WhenGivenPuzzleInput_ItShouldReturnExpectedValue()
{
var input = await GetPuzzleInput();
var result = TopoMap.From(input).GetTrailheadScores().Sum();
await Assert.That(result).IsEqualTo(496);
}
[Test]
public async Task GetTrailheadRatings_WhenCalledWithExampleInput_ItShouldReturnExpectedValues()
{
var expectedValues = new List<int>()
{
20,
24,
10,
4,
1,
4,
5,
8,
5,
};
var result = TopoMap.From(_exampleInput).GetTrailheadRatings();
await Assert.That(result).IsEquivalentTo(expectedValues);
await Assert.That(result.Sum()).IsEqualTo(81);
}
[Test]
public async Task PartTwo_WhenGivenPuzzleInput_ItShouldReturnExpectedValue()
{
var input = await GetPuzzleInput();
var result = TopoMap.From(input).GetTrailheadRatings().Sum();
await Assert.That(result).IsEqualTo(1120);
}
}
10/HoofIt/Direction.cs
+9
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@@ -0,0 +1,9 @@
namespace HoofIt;
record Direction(int XD, int YD)
{
public static Direction Up = new(0, -1);
public static Direction Down = new(0, 1);
public static Direction Left = new(-1, 0);
public static Direction Right = new(1, 0);
}
10/HoofIt/Position.cs
+35
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@@ -0,0 +1,35 @@
namespace HoofIt;
record Position(int X, int Y, int Height)
{
public bool TryGetNextPosition(Direction direction, string[] grid, out Position nextPosition)
{
var x = X + direction.XD;
var y = Y + direction.YD;
nextPosition = new(x, y, -1);
var isOffGrid = IsOffGrid(nextPosition, grid);
if (isOffGrid)
{
return false;
}
if (int.TryParse(grid[y][x].ToString(), out var nextPositionHeight) is false)
{
return false;
}
nextPosition = nextPosition with { Height = nextPositionHeight };
return true;
}
private static bool IsOffGrid(Position position, string[] grid)
{
return position.X < 0 ||
position.X > grid[0].Length - 1 ||
position.Y > grid.Length - 1 ||
position.Y < 0;
}
}
10/HoofIt/Program.cs
+8 -125
View File
@@ -1,5 +1,7 @@
using System.Diagnostics;
using HoofIt;
if (args.Length is 0)
{
Console.WriteLine("Please provide a path to the input file.");
@@ -20,132 +22,13 @@ stopwatch.Start();
var map = TopoMap.From(input);
// i'm going to to walk over the grid
// i'm going to only worry about places where
// there is a zero
var nums = isPart2
? map.GetTrailheadRatings()
: map.GetTrailheadScores();
// need to check if we are on a nine
// before we explore...also we should
// be able to add to score here
var result = nums.Sum();
// when i encounter a zero i need to begin
// exploring nearby tiles that increment by 1
// in each left, right, up, down direction
// any adj tile that fits this...is a tile i
// need to also explore
var nameOfStat = isPart2 ? "ratings" : "scores";
stopwatch.Stop();
Console.WriteLine($". ({stopwatch.ElapsedMilliseconds}ms)");
class TopoMap
{
private static Direction[] _directions = [
Direction.Up,
Direction.Down,
Direction.Left,
Direction.Right,
];
private readonly string[] _grid;
private TopoMap(string[] input)
{
_grid = input;
}
public static TopoMap From(string[] input) => new(input);
// TODO: This actually needs to be GetTrailHeadScore
// I want to perform this search when I know I've reached
// a trail head.
public int GetTrailHeadScores()
{
var trailheadScore = 0;
var visitedPositions = new HashSet<Position>();
var positionsToVisit = new Queue<Position>();
var startingX = 0;
var startingY = 0;
var startingHeight = int.Parse(_grid[startingY][startingX].ToString());
positionsToVisit.Enqueue(new(startingX, startingY, startingHeight));
while (positionsToVisit.Count != 0)
{
var currentPosition = positionsToVisit.Dequeue();
if (visitedPositions.Contains(currentPosition))
{
continue;
}
visitedPositions.Add(currentPosition);
if (currentPosition.Height is 9)
{
trailheadScore++;
continue;
}
foreach (var direction in _directions)
{
if (currentPosition.TryGetNextPosition(direction, _grid, out var newPosition) is false)
{
continue;
}
if (visitedPositions.Contains(newPosition))
{
continue;
}
var heightDifference = newPosition.Height - currentPosition.Height;
if (heightDifference is not 1)
{
continue;
}
positionsToVisit.Enqueue(newPosition);
}
}
return trailheadScore;
}
}
record Position(int X, int Y, int Height)
{
public bool TryGetNextPosition(Direction direction, string[] grid, out Position position)
{
var x = X + direction.XD;
var y = Y + direction.YD;
position = new(x, y, -1);
var isOffGrid = IsOffGrid(position, grid);
if (isOffGrid)
{
return false;
}
position = position with { Height = grid[y][x] };
return true;
}
private bool IsOffGrid(Position position, string[] grid)
{
return position.X < 0 ||
position.X > grid[0].Length - 1 ||
position.Y > grid.Length - 1 ||
position.Y < 0;
}
}
record Direction(int XD, int YD)
{
public static Direction Up = new(0, -1);
public static Direction Down = new(0, 1);
public static Direction Left = new(-1, 0);
public static Direction Right = new(1, 0);
}
Console.WriteLine($"The sum of the {nameOfStat} of all trailheads is {result}. ({stopwatch.ElapsedMilliseconds}ms)");
10/HoofIt/TopoMap.cs
+119
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@@ -0,0 +1,119 @@
namespace HoofIt;
class TopoMap
{
private static readonly Direction[] Directions = [
Direction.Up,
Direction.Down,
Direction.Left,
Direction.Right,
];
private readonly string[] _grid;
private TopoMap(string[] input)
{
_grid = input;
}
public static TopoMap From(string[] input) => new(input);
public List<int> GetTrailheadRatings()
{
var ratings = new List<int>();
WalkMap((x, y) =>
{
var hasHeight = int.TryParse(_grid[y][x].ToString(), out var currentHeight);
if (hasHeight is false || currentHeight is not 0)
{
return;
}
var rating = GetPathsForTrail(new(x, y, currentHeight));
ratings.Add(rating);
});
return ratings;
}
public List<int> GetTrailheadScores()
{
var trailScores = new List<int>();
WalkMap((x, y) =>
{
var hasHeight = int.TryParse(_grid[y][x].ToString(), out var currentHeight);
if (hasHeight is false || currentHeight is not 0)
{
return;
}
var score = GetPathsForTrail(new(x, y, currentHeight), needToBeUnique: true);
trailScores.Add(score);
});
return trailScores;
}
private int GetPathsForTrail(Position trailhead, bool needToBeUnique = false)
{
var trailheadScore = 0;
var visitedPositions = new HashSet<Position>();
var positionsToVisit = new Queue<Position>();
positionsToVisit.Enqueue(trailhead);
while (positionsToVisit.Count is not 0)
{
var currentPosition = positionsToVisit.Dequeue();
if (needToBeUnique && visitedPositions.Contains(currentPosition))
{
continue;
}
visitedPositions.Add(currentPosition);
if (currentPosition.Height is 9)
{
trailheadScore++;
continue;
}
foreach (var direction in Directions)
{
if (currentPosition.TryGetNextPosition(direction, _grid, out var newPosition) is false)
{
continue;
}
var heightDifference = newPosition.Height - currentPosition.Height;
if (heightDifference is not 1)
{
continue;
}
positionsToVisit.Enqueue(newPosition);
}
}
return trailheadScore;
}
private void WalkMap(Action<int, int> callback)
{
for (var y = 0; y < _grid.Length; y++)
{
var row = _grid[y];
for (var x = 0; x < row.Length; x++)
{
callback(x, y);
}
}
}
}
README.md
+1
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@@ -53,3 +53,4 @@ dotnet build
| 07 | [Problem](./07/PROBLEM.md) | [Solution](./07/BridgeRepair/) | Not perfect or pretty, but good enough |
| 08 | [Problem](./08/PROBLEM.md) | [Solution](./08/ResonantCollinearity/) | Without some help from chat I don't know where I'd be...to be fair the description kind of mislead me. |
| 09 | [Problem](./09/PROBLEM.md) | [Solution](./09/DiskFragmenter/) | Doing things with indexes is error prone. |
| 10 | [Problem](./10/PROBLEM.md) | [Solution](./10/HoofIt/) | I recognized the solution for this based on pattern from last year. Solved using BFS. |