// set pole as visited
private void _SetPoint(ChessCordinates poleCordinates)
{
if (poleCordinates.GetX() < 9 && poleCordinates.GetX() > 0 &&
poleCordinates.GetY() < 9 && poleCordinates.GetY() > 0)
{
this._chessMatrix[poleCordinates.GetX() - 1, poleCordinates.GetY() - 1] = true;
}
}
// helps to check if pole haven't been visited
// return true if pole have been visited
// return false if not
private bool _CheckPoint(ChessCordinates poleCordinates)
{
if (poleCordinates.IsValid())
{
return(this._chessMatrix[poleCordinates.GetX() - 1, poleCordinates.GetY() - 1]);
}
else
{
return(false);
}
}
private ChessCordinates[] _shifts; // posible shifts to calculate the pole
public KnightExplorer(ChessCordinates startCordinates, ChessCordinates endCordinates)
{
this._chessMatrix = new bool[8, 8];
this._ways = new Queue();
this._endCordinates = endCordinates;
this._shifts = new ChessCordinates[8] {
new ChessCordinates(-2, 1), new ChessCordinates(-1, 2),
new ChessCordinates(1, 2), new ChessCordinates(2, 1),
new ChessCordinates(2, -1), new ChessCordinates(1, -2),
new ChessCordinates(-1, -2), new ChessCordinates(-2, -1)
};
// add start cordinates to ways queue
ArrayList tempList = new ArrayList();
tempList.Add(startCordinates);
this._ways.Enqueue(tempList);
}
// finds way from start cordinates to end cordinates
// (breadth-first seacrh)
// return array with way from end cords to start cords
public ArrayList FindWay()
{
while (true)
{
// eject head way and set point on chess board
ArrayList headWay = (ArrayList)this._ways.Dequeue();
_SetPoint((ChessCordinates)headWay[0]);
// check all reachable poles, add them to ways queue if they are not equal end cords
foreach (ChessCordinates shift in _shifts)
{
// calculate new pole
ChessCordinates newPole = shift + (ChessCordinates)headWay[0];
// if new is possible and pole haven't been visited, add way with it to ways queue
if (newPole.IsValid() && (_CheckPoint(newPole) == false))
{
// set new way
ArrayList newWay = new ArrayList()
{
newPole
};
newWay.AddRange(headWay);
// if exploring reachs end cords, return result
if ((ChessCordinates)newWay[0] == _endCordinates)
{
return(newWay);
}
// else add new way to ways queues
else
{
_ways.Enqueue(newWay);
}
}
}
}
}
