/// <summary>
/// Iterative breadth first algorithm
/// </summary>
/// <param name="row">Row to start at</param>
/// <param name="column">Column to start at</param>
/// <returns>True - if path is found, false - if path is not found.</returns>
private BreadthFirstResult ExecuteInternal(int row, int column)
{
var result = new BreadthFirstResult();
if (row == 0 || row == _labyrinthHeight - 1 || column == 0 || column == _labyrinthWidth - 1)
{
result.IsSuccess = true;
GetTrace(row, column, result);
return(result);
}
var newRow = 0;
var newColumn = 0;
while (_close <= _new)
{
row = _fRow[_close];
column = _fColumn[_close];
//Loop over production rules
for (int i = 0; i < 4; i++)
{
//Calculate new coordinates
newRow = row + _cRow[i];
newColumn = column + _cColumn[i];
//if cell is free
if (_operationalLabyrinth[newRow, newColumn] == 0)
{
_operationalLabyrinth[newRow, newColumn] = _operationalLabyrinth[row, column] + 1;
if (newRow == 0 || newRow == _labyrinthHeight - 1 || newColumn == 0 || newColumn == _labyrinthWidth - 1)
{
GetTrace(newRow, newColumn, result);
result.IsSuccess = true;
return(result);
}
_new++;
_fRow[_new] = newRow;
_fColumn[_new] = newColumn;
}
}
_close++;
}
return(result);
}
private void GetTrace(int endRow, int endColumn, BreadthFirstResult result)
{
var newRow = 0;
var newColumn = 0;
var endRowCopy = endRow;
var endColumnCopy = endColumn;
var labCopy = (int[, ])_labyrinth.Clone();
var endRowNotChanged = endRow;
var endColumnNotChanged = endColumn;
_labyrinth[endRow, endColumn] = _operationalLabyrinth[endRow, endColumn];
var path = new List <KeyValuePair <int, int> >();
path.Add(new KeyValuePair <int, int>(endRow, endColumn));
//Collect path
do
{
for (int k = 3; k >= 0; k--)
{
newRow = endRow + _cRow[k];
newColumn = endColumn + _cColumn[k];
//if in labyrinth
if (newRow > 0 && newRow < _labyrinthHeight - 1 && newColumn > 0 && newColumn < _labyrinthWidth - 1)
{
//if previous number
if (_operationalLabyrinth[newRow, newColumn] == _operationalLabyrinth[endRow, endColumn] - 1)
{
//previous step found
_labyrinth[newRow, newColumn] = _operationalLabyrinth[newRow, newColumn];
endRow = newRow;
endColumn = newColumn;
path.Add(new KeyValuePair <int, int>(endRow, endColumn));
}
}
}
} while (_labyrinth[endRow, endColumn] != 2);
//Reverse path, first element = start element
path.Reverse();
result.Path = path;
var newN = 0;
var close = 0;
newColumn = 0;
newRow = 0;
var processNextIteration = new List <KeyValuePair <int, int> >();
var processNextIterationCopy = new List <KeyValuePair <int, int> >();
//Collect trace
for (int i = 0; i < path.Count; i++)
{
processNextIteration = new List <KeyValuePair <int, int> >(processNextIterationCopy);
processNextIterationCopy.Clear();
_loggerService.Write($"Wave {i}, label L=\"{_operationalLabyrinth[path[i].Key, path[i].Value]}\"");
if (i == 0)
{
_loggerService.Write($". Initial position: X={path[i].Value + 1}, Y={path[i].Key + 1}, NEWN={newN + 1}");
processNextIterationCopy.Add(new KeyValuePair <int, int>(path[i].Key, path[i].Value));
_loggerService.WriteLine("");
continue;
}
_loggerService.WriteLine("");
for (int j = 0; j < processNextIteration.Count; j++)
{
_loggerService.WriteLine($" Close CLOSE={close + 1}, X={processNextIteration[j].Value + 1}, Y={processNextIteration[j].Key + 1}.");
close++;
for (int k = 0; k < 4; k++)
{
newRow = processNextIteration[j].Key + _cRow[k];
newColumn = processNextIteration[j].Value + _cColumn[k];
_loggerService.Write($" R{k + 1}. X={newColumn + 1}, Y={newRow + 1}.");
//if in labyrinth
if ((newRow > 0 && newRow < _labyrinthHeight - 1 && newColumn > 0 && newColumn < _labyrinthWidth - 1) ||
(newRow == endRowNotChanged && newColumn == endColumnNotChanged))
{
//if terminal.
if (newRow == endRowNotChanged && newColumn == endColumnNotChanged)
{
endRowCopy = newRow;
endColumnCopy = newColumn;
newN++;
_loggerService.Write($" Free. NEWN={newN + 1}. Terminal.");
processNextIterationCopy.Add(new KeyValuePair <int, int>(newRow, newColumn));
_loggerService.WriteLine("");
goto terminalCheckpoint;
}
//if next number
else if (_operationalLabyrinth[newRow, newColumn] + 1 == _operationalLabyrinth[endRowCopy, endColumnCopy])
{
endRowCopy = newRow;
endColumnCopy = newColumn;
newN++;
_loggerService.Write($" Free. NEWN={newN + 1}");
processNextIterationCopy.Add(new KeyValuePair <int, int>(newRow, newColumn));
}
//if free
else if (labCopy[newRow, newColumn] == 0)
{
if (_fRow[newN + 1] == newRow && _fColumn[newN + 1] == newColumn)
{
newN++;
_loggerService.Write($" Free. NEWN={newN + 1}");
processNextIterationCopy.Add(new KeyValuePair <int, int>(newRow, newColumn));
}
else
{
_loggerService.Write($" CLOSED OR OPEN.");
}
}
//if wall
else if (labCopy[newRow, newColumn] == 1)
{
_loggerService.Write($" Wall.");
}
}
else
{
_loggerService.Write($" Wall.");
}
_loggerService.WriteLine("");
}
}
}
terminalCheckpoint:
//Compute rules
var rules = new List <string>();
for (int i = 0; i < path.Count; i++)
{
for (int j = 0; j < 4; j++)
{
if (i != path.Count - 1 && path[i + 1].Value == path[i].Value + _cColumn[j] && path[i + 1].Key == path[i].Key + _cRow[j])
{
rules.Add($"R{j + 1}");
}
}
}
result.Rules = rules;
}