static int ShortestPathInMaze(int[,] maze, Coordinate start, Coordinate end)
{
Queue <Coordinate> queue = new Queue <Coordinate>();
HashSet <Coordinate> visitedLocations = new HashSet <Coordinate>();
visitedLocations.Add(new Coordinate()
{
X = 0, Y = 0
});
List <Coordinate> nextMoves = FindNextMoves(maze, start, ref visitedLocations);
AddNextMovesToQueue(ref queue, nextMoves);
int path = 0;
while (queue.Count > 0)
{
Coordinate location = queue.Dequeue();
if (location.X == end.X && location.Y == end.Y)
{
break;
}
nextMoves = FindNextMoves(maze, location, ref visitedLocations);
AddNextMovesToQueue(ref queue, nextMoves);
path++;
}
return(path);
}
static bool IsLocationVisited(ref HashSet <Coordinate> visitedLocations, int x, int y)
{
Coordinate coor = new Coordinate()
{
X = x, Y = y
};
if (visitedLocations.Contains(coor))
{
return(true);
}
return(false);
}
static List <Coordinate> FindNextMoves(int[,] maze, Coordinate currLocation, ref HashSet <Coordinate> visitedLocations)
{
List <Coordinate> moves = new List <Coordinate>();
if (currLocation.X > 0)
{
if (!IsLocationVisited(ref visitedLocations, currLocation.X - 1, currLocation.Y) &&
maze[currLocation.X - 1, currLocation.Y] == 1)
{
var coor = new Coordinate()
{
X = currLocation.X - 1, Y = currLocation.Y
};
// add to next moves and mark visited
moves.Add(coor);
visitedLocations.Add(coor);
}
}
if (currLocation.Y > 0)
{
if (!IsLocationVisited(ref visitedLocations, currLocation.X, currLocation.Y - 1) &&
maze[currLocation.X, currLocation.Y - 1] == 1)
{
var coor = new Coordinate()
{
X = currLocation.X, Y = currLocation.Y - 1
};
// add to next moves and mark visited
moves.Add(coor);
visitedLocations.Add(coor);
}
}
if (currLocation.X < maze.GetLength(0) - 1)
{
if (!IsLocationVisited(ref visitedLocations, currLocation.X + 1, currLocation.Y) &&
maze[currLocation.X + 1, currLocation.Y] == 1)
{
var coor = new Coordinate()
{
X = currLocation.X + 1, Y = currLocation.Y
};
// add to next moves and mark visited
moves.Add(coor);
visitedLocations.Add(coor);
}
}
if (currLocation.Y < maze.GetLength(1) - 1)
{
if (!IsLocationVisited(ref visitedLocations, currLocation.X, currLocation.Y + 1) &&
maze[currLocation.X, currLocation.Y + 1] == 1)
{
var coor = new Coordinate()
{
X = currLocation.X, Y = currLocation.Y + 1
};
// add to next moves and mark visited
moves.Add(coor);
visitedLocations.Add(coor);
}
}
return(moves);
}
