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[2022] Day9 added

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Tiago Garcia 2023-06-09 00:43:55 +01:00
parent f8b6784df3
commit 696151a23c
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2 changed files with 103 additions and 61 deletions
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30
Utils/Extensions.cs
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@ -2,6 +2,16 @@ namespace AdventOfCode.Utils;
public static class Extensions
{
public static int Signal(this int x)
{
return x switch
{
< 0 => -1,
> 0 => 1,
_ => 0
};
}
/// <summary>
/// Returns a slice of the given list
/// </summary>
@ -76,4 +86,24 @@ public static class Extensions
ret.Add(entry.Key, entry.Value.Clone());
return ret;
}
public static void Fill<T>(this List<T> list, int count, T element)
where T : ICloneable
{
for (int i = 0; i < count; i++)
list.Add(element);
}
public static void Fill<T>(this List<List<T>> list, int count, List<T> element)
{
for (int i = 0; i < count; i++)
list.Add(element.Clone());
}
public static void Set<T>(this List<T> list, int index, T element)
{
List<T> backup = list.Clone();
list.Clear();
for (int i = 0; i < list.Count; i++) list.Add(i == index ? element : list[i]);
}
}

134
Year2022/Day9.cs
View File

@ -1,87 +1,99 @@
using AdventOfCode.Utils;
namespace AdventOfCode.Year2022;
public class Day9
{
private static readonly List<(char, int)> Moves = new();
private static readonly Dictionary<char, List<int>> Position = new()
{
['H'] = new List<int>(),
['T'] = new List<int>()
};
public Day9()
{
Console.WriteLine("Day9 Solution");
List<(char, int)> moves = new List<(char, int)>();
File.ReadAllLines("inputs/day9.txt").ToList().ForEach(line =>
{
string[] split = line.Split(" ");
Moves.Add((Convert.ToChar(split[0]), Convert.ToInt32(split[1])));
moves.Add((Convert.ToChar(split[0]), Convert.ToInt32(split[1])));
});
Console.WriteLine($"Part1 Result: {Part1()}");
Console.WriteLine($"Part2 Result: {Part2()}");
Console.WriteLine($"Part1 Result: {GetPositionCount(moves, 2)}");
Console.WriteLine($"Part2 Result: {GetPositionCount(moves, 10)}");
Console.WriteLine("\n=============================\n");
}
private static int Part1()
private static int GetPositionCount(List<(char, int)> moves, int knots)
{
Position['H'] = new[] {0, 0}.ToList();
Position['T'] = new[] {0, 0}.ToList();
HashSet<(int, int)> usedPositions = new HashSet<(int, int)>();
List<List<int>> currentPositions = new List<List<int>>();
currentPositions.Fill(knots, new List<int>(new[]{0,0}));
HashSet<(int, int)> tailHistory = new HashSet<(int, int)>();
foreach ((char, int) move in Moves)
{
List<int> head = Position['H'];
List<int> tail = Position['T'];
for (int i = 0; i < move.Item2; i++)
foreach ((char, int) move in moves)
for (int moveN = 0; moveN < move.Item2; moveN++)
{
if (move.Item1 == 'U')
int[] vector = GetVector(move.Item1);
int[] previousTailPosition = currentPositions[0].ToArray();
currentPositions[0] = UpdateHead(vector, currentPositions[0]);
for (int tailN = 0; tailN < knots-1; tailN++)
{
head[1]++;
if (ValidatePosition()) continue;
tail[1]++;
tail[0] += head[0] - tail[0];
int[] nextPreviousTailPosition = currentPositions[tailN + 1].ToArray();
currentPositions[tailN + 1] = UpdateTail(currentPositions[tailN], currentPositions[tailN + 1], previousTailPosition);
previousTailPosition = nextPreviousTailPosition;
if (tailN == knots - 2)
tailHistory.Add((currentPositions[knots - 1][0], currentPositions[knots - 1][1]));
}
else if (move.Item1 == 'D')
{
head[1]--;
if (ValidatePosition()) continue;
tail[1]--;
tail[0] += head[0] - tail[0];
}
else if (move.Item1 == 'R')
{
head[0]++;
if (ValidatePosition()) continue;
tail[0]++;
tail[1] += head[1] - tail[1];
}
else if (move.Item1 == 'L')
{
head[0]--;
if (ValidatePosition()) continue;
tail[0]--;
tail[1] += head[1] - tail[1];
}
usedPositions.Add((tail[0], tail[1]));
}
}
return usedPositions.Count;
return tailHistory.Count;
}
private static int Part2()
private static List<int> UpdateHead(int[] vector, List<int> currentPosition)
{
Position['H'] = new[] {0, 0}.ToList();
Position['T'] = new[] {0, 0}.ToList();
HashSet<(int, int)> usedPositions = new HashSet<(int, int)>();
foreach ((char, int) move in Moves)
{
}
return usedPositions.Count;
currentPosition[0] += vector[0];
currentPosition[1] += vector[1];
return new List<int> { currentPosition[0], currentPosition[1] };
}
private static bool ValidatePosition()
=> Position['H'][0] - Position['T'][0] is > -2 and < 2 && Position['H'][1] - Position['T'][1] is > -2 and < 2;
private static List<int> UpdateTail(List<int> currentHeadPosition, List<int> currentTailPosition, int[] previousTailPosition)
{
List<int> head = new List<int>
{
currentHeadPosition[0] - previousTailPosition[0],
currentHeadPosition[1] - previousTailPosition[1]
};
if (Math.Abs(currentHeadPosition[0] - currentTailPosition[0]) > 1 ||
Math.Abs(currentHeadPosition[1] - currentTailPosition[1]) > 1)
{
if (previousTailPosition[0] == currentTailPosition[0] ||
previousTailPosition[1] == currentTailPosition[1])
return new List<int>
{
currentTailPosition[0] + head[0],
currentTailPosition[1] + head[1]
};
List<int> difference = new List<int>
{
currentHeadPosition[0] - currentTailPosition[0],
currentHeadPosition[1] - currentTailPosition[1]
};
return new List<int>
{
currentTailPosition[0] + difference[0].Signal() * Math.Min(Math.Abs(difference[0]), 1),
currentTailPosition[1] + difference[1].Signal() * Math.Min(Math.Abs(difference[1]), 1)
};
}
return currentTailPosition;
}
private static int[] GetVector(char direction)
{
return direction switch
{
'U' => new[] { 1, 0 },
'D' => new[] { -1, 0 },
'R' => new[] { 0, 1 },
'L' => new[] { 0, -1 },
_ => new[] { 0, 0 }
};
}
}