public LinkedList<Integer> getAdjList(int i) {
if (adjacencies.containsKey(i)) {
return adjacencies.get(i);
}
LinkedList<Integer> neighbors = new LinkedList<Integer>();
int column = i % numColumns;
int row = i / numColumns;
BoardCell adj;
BoardCell cell = getCellAt(i);
adjacencies.put(i, neighbors);
if (cell.isRoom()) {
// only midget doorways have adjacencies, and they only have one arm, so short-circuit
// if a door was placed facing an edge, this would be invalid, but the board should not be set
// up that way
if (cell.isDoorway()) {
switch (((RoomCell) cell).getDoorDirection()) {
case RIGHT:
neighbors.add(i + 1);
break;
case LEFT:
neighbors.add(i - 1);
break;
case UP:
neighbors.add(i - numColumns);
break;
case DOWN:
neighbors.add(i + numColumns);
break;
}
}
return neighbors;
}
if (column > 0) {
adj = getCellAt(i - 1); // the cell to the left
if (adj.isWalkway()
|| (adj.isDoorway() && ((RoomCell) adj).getDoorDirection() == DoorDirection.RIGHT)) {
neighbors.add(i - 1);
}
}
if (column < numColumns - 1) {
adj = getCellAt(i + 1); // the cell to the right
if (adj.isWalkway()
|| (adj.isDoorway() && ((RoomCell) adj).getDoorDirection() == DoorDirection.LEFT)) {
neighbors.add(i + 1);
}
}
if (row > 0) {
adj = getCellAt(i - numColumns); // the cell above
if (adj.isWalkway()
|| (adj.isDoorway() && ((RoomCell) adj).getDoorDirection() == DoorDirection.DOWN)) {
neighbors.add(i - numColumns);
}
}
if (row < numRows - 1) {
adj = getCellAt(i + numColumns); // the cell below
if (adj.isWalkway()
|| (adj.isDoorway() && ((RoomCell) adj).getDoorDirection() == DoorDirection.UP)) {
neighbors.add(i + numColumns);
}
}
return neighbors;
}
