public override bool Equals(object obj)
{
if (obj == null || GetType() != obj.GetType())
{
return(false);
}
MazeState mazeState = (MazeState)obj;
return((Position == mazeState.Position) && (Distance == mazeState.Distance));
}
public static void Main(string[] args)
{
string source = File.ReadAllText(@"..\..\input.txt");
source = source.Remove(source.Length - 1);
List <string> instructions = source.Split('\n').ToList();
char[,] maze = CreateMaze(instructions);
List <char> locations = new List <char> {
'0', '1', '2', '3', '4', '5', '6', '7'
};
List <Point> points = locations.Select(l => FindPoint(maze, l)).ToList();
List <List <char> > locationPermutations = Permutations.GeneratePermutations(locations);
locationPermutations = locationPermutations.Where(lp => lp[0] == '0').ToList();
Dictionary <string, int> storedDistances = new Dictionary <string, int>();
for (int i = 0; i < points.Count; i++)
{
for (int j = 0; j < points.Count; j++)
{
MazeState state = FindShortestPath(maze, points[i], points[j]);
storedDistances.Add(i + "" + j, state.Distance);
}
}
List <PathDistance> pathDistances = locationPermutations.Select(lp => new PathDistance {
Locations = lp, Distance = GetTotalDistance(storedDistances, lp)
}).ToList();
int partOne = pathDistances.Min().Distance;
foreach (List <char> locationPermutation in locationPermutations)
{
locationPermutation.Add('0');
}
pathDistances = locationPermutations.Select(lp => new PathDistance {
Locations = lp, Distance = GetTotalDistance(storedDistances, lp)
}).ToList();
int partTwo = pathDistances.Min().Distance;
Console.WriteLine("Part one = {0}", partOne);
Console.WriteLine("Part two = {0}", partTwo);
Console.ReadLine();
}
private static MazeState FindShortestPath(char[,] maze, Point start, Point target)
{
Queue <MazeState> statesQueue = new Queue <MazeState>(new[] { new MazeState(start, 0) });
MazeState finishState = null;
while (statesQueue.Count > 0)
{
MazeState currentState = statesQueue.Dequeue();
if (currentState.Position == target)
{
finishState = finishState ?? currentState;
}
else
{
HashSet <MazeState> possibleMoves = new HashSet <MazeState>
{
new MazeState(currentState.Position.X + 1, currentState.Position.Y, currentState.Distance + 1),
new MazeState(currentState.Position.X - 1, currentState.Position.Y, currentState.Distance + 1),
new MazeState(currentState.Position.X, currentState.Position.Y + 1, currentState.Distance + 1),
new MazeState(currentState.Position.X, currentState.Position.Y - 1, currentState.Distance + 1)
};
if (finishState != null)
{
possibleMoves =
new HashSet <MazeState>(possibleMoves.Where(move => move.Distance < finishState.Distance));
}
foreach (MazeState newState in possibleMoves)
{
if (IsOpenSpace(maze, newState.Position.X, newState.Position.Y) && !statesQueue.Contains(newState))
{
statesQueue.Enqueue(newState);
}
}
}
}
return(finishState);
}
