private static boolean[] search(Position playerPos, Box box, Map map) {
char[][] board = map.getMap();
// Directions[0-4] = west, east, north, south!
boolean[] directions = new boolean[4];
for (int i = 0; i < 4; i++) {
directions[i] = false;
}
Position boxPos = box.getPosition();
Position west = new Position(boxPos.getRow(), boxPos.getCol() - 1);
Position east = new Position(boxPos.getRow(), boxPos.getCol() + 1);
Position north = new Position(boxPos.getRow() - 1, boxPos.getCol());
Position south = new Position(boxPos.getRow() + 1, boxPos.getCol());
boolean[][] visited = new boolean[map.getRows()][map.getCols()];
// Initialize visited to false
for (int row = 0; row < map.getRows(); row++) {
for (int col = 0; col < map.getCols(); col++) {
visited[row][col] = false;
}
}
Queue<Position> q = new LinkedList<Position>();
q.add(playerPos);
visited[playerPos.getRow()][playerPos.getCol()] = true;
while (!q.isEmpty()) {
Position currPos = q.remove();
// may reach left position of the box
if (currPos.isEqualTo(west)) {
directions[0] = true;
}
// may reach right position of the box
if (currPos.isEqualTo(east)) {
directions[1] = true;
}
// may reach peter north position of the box
if (currPos.isEqualTo(north)) {
directions[2] = true;
}
// may reach south position of the box
if (currPos.isEqualTo(south)) {
directions[3] = true;
}
for (int direction = 0; direction < 4; direction++) {
if (direction == WEST) {
Position newPos = new Position(currPos.getRow(), currPos.getCol() - 1);
if (!visited[newPos.getRow()][newPos.getCol()] && isAvailiable(board, newPos)) {
visited[newPos.getRow()][newPos.getCol()] = true;
q.add(newPos);
}
} else if (direction == EAST) {
Position newPos = new Position(currPos.getRow(), currPos.getCol() + 1);
if (!visited[newPos.getRow()][newPos.getCol()] && isAvailiable(board, newPos)) {
visited[newPos.getRow()][newPos.getCol()] = true;
q.add(newPos);
}
} else if (direction == NORTH) {
Position newPos = new Position(currPos.getRow() - 1, currPos.getCol());
if (!visited[newPos.getRow()][newPos.getCol()] && isAvailiable(board, newPos)) {
visited[newPos.getRow()][newPos.getCol()] = true;
q.add(newPos);
}
} else if (direction == SOUTH) {
Position newPos = new Position(currPos.getRow() + 1, currPos.getCol());
if (!visited[newPos.getRow()][newPos.getCol()] && isAvailiable(board, newPos)) {
visited[currPos.getRow()][currPos.getCol()] = true;
q.add(newPos);
}
}
}
}
return directions;
}
private boolean canMoveBoxAt(PositionSwitcher movement, Box box) {
if (box != null) {
Position newBoxPos = movement.change(box.getPosition());
return isEmpty(newBoxPos);
}
return false;
}
/** Find all possible directions from where the player is standing, to boxes that can be pushed */
public static ArrayList<Move> findPossibleMoves(Map map) {
ArrayList<Move> possibleMoves = new ArrayList<Move>();
Position playerPos = map.getPlayerPosition();
ArrayList<Box> boxes = map.getAllBoxes();
boolean[] directions = new boolean[4];
for (int boxNr = 0; boxNr < boxes.size(); boxNr++) {
Box currBox = boxes.get(boxNr);
directions = search(playerPos, currBox, map);
for (int i = 0; i < 4; i++) {
if (directions[i]) {
if (i == WEST) { // Push the box east
Position newBoxPos =
new Position(currBox.getPosition().getRow(), currBox.getPosition().getCol() + 1);
if (legalPush(newBoxPos, map)) {
Move move = new Move(boxNr, newBoxPos);
possibleMoves.add(move);
} else {
continue;
}
} else if (i == EAST) { // Push the box west
Position newBoxPos =
new Position(currBox.getPosition().getRow(), currBox.getPosition().getCol() - 1);
if (legalPush(newBoxPos, map)) {
Move move = new Move(boxNr, newBoxPos);
possibleMoves.add(move);
}
} else if (i == NORTH) { // Push the box south
Position newBoxPos =
new Position(currBox.getPosition().getRow() + 1, currBox.getPosition().getCol());
if (legalPush(newBoxPos, map)) {
Move move = new Move(boxNr, newBoxPos);
possibleMoves.add(move);
}
} else if (i == SOUTH) { // Push the box north
Position newBoxPos =
new Position(currBox.getPosition().getRow() - 1, currBox.getPosition().getCol());
if (legalPush(newBoxPos, map)) {
Move move = new Move(boxNr, newBoxPos);
possibleMoves.add(move);
}
}
}
}
}
return possibleMoves;
}
private void insert(Box n, ArrayList<Box> a, int i) {
for (;
i > 0 && ((Comparable<Integer>) a.get(i - 1).getPosition()).compareTo(n.getPosition()) > 0;
i--) a.set(i, a.get(i - 1));
a.set(i, n);
}
