private bool SolveAux(Grid initial)
{
if (initial.IsSolved())
return true;
int pos = GetNextPosition(initial);
var listMoves = initial.GetAvailableNumbersFor(pos);
foreach (var move in listMoves)
{
initial.Place(move,pos);
if (SolveAux(initial))
return true;
initial.Place(0,pos);
}
return false;
}