public FastCollinearPoints(
Point[] points) { // finds all line segments containing 4 or more points
if (points == null) throw new NullPointerException();
for (int i = 0; i < points.length; i++) {
if (points[i] == null) throw new NullPointerException();
}
lineSegments = new Queue<LineSegment>();
for (int i = 0; i < points.length; i++) {
// copy natural sorted array
Point[] cPoints = new Point[points.length];
for (int j = 0; j < points.length; j++) {
if (i != j && points[i].compareTo(points[j]) == 0) throw new IllegalArgumentException();
cPoints[j] = points[j];
}
// sort by slope with points[i]
Arrays.sort(cPoints, points[i].slopeOrder());
Point largest = cPoints[0];
Point smallest = cPoints[0];
int ccount = 1;
for (int j = 1; j < points.length; j++) {
if (points[i].slopeTo(cPoints[j - 1]) == points[i].slopeTo(cPoints[j])) {
if (smallest.compareTo(cPoints[j]) > 0) smallest = cPoints[j];
else if (largest.compareTo(cPoints[j]) < 0) largest = cPoints[j];
ccount++;
} else {
if (ccount >= 3 && points[i].compareTo(smallest) < 0) {
lineSegments.enqueue(new LineSegment(points[i], largest));
segmentCount++;
}
ccount = 1;
smallest = cPoints[j];
largest = cPoints[j];
}
}
if (ccount >= 3 && points[i].compareTo(smallest) < 0) {
lineSegments.enqueue(new LineSegment(points[i], largest));
segmentCount++;
}
}
}
public static void listFiles(File file, Queue<? super String> f_names, int indent) {
if (file.isDirectory()) {
File[] files = file.listFiles();
if (files == null) return;
Arrays.stream(files).forEach(f -> listFiles(f, f_names, indent + 2));
} else if (file.isFile()) {
String format_str = String.format("%%%ds%%s\n", indent);
f_names.enqueue(String.format(format_str, "", file.getName()));
}
}
private ShortestPath findShortestPath(int v, int w) {
if (!isValid(v)) {
throw new java.lang.NullPointerException("Invalid v parameter");
}
if (!isValid(w)) {
throw new java.lang.NullPointerException("Ivalid w parameter");
}
Queue<Integer> q = new Queue<Integer>();
boolean[] marked = new boolean[G.V()];
int[] distTo = new int[G.V()];
q.enqueue(v);
q.enqueue(w);
marked[v] = true;
marked[w] = true;
distTo[v] = 0;
distTo[w] = 0;
while (!q.isEmpty()) {
int a = q.dequeue();
for (int b : G.adj(a)) {
if (marked[b]) {
int length = distTo[b] + distTo[a] + 1;
ShortestPath sp = new ShortestPath();
sp.ancestor = b;
sp.length = length;
return sp;
}
distTo[b] = distTo[a] + 1;
marked[b] = true;
q.enqueue(b);
}
}
return null;
}
// all neighboring boards
public Iterable<Board> neighbors() {
Queue<Board> result = new Queue<>();
int[][] directions = new int[][] {{-1, 0}, {1, 0}, {0, -1}, {0, 1}}; // up, down, left, right
for (int[] direc : directions) {
Board board = new Board(this);
boolean success =
swap(
board.copy,
board.blankX,
board.blankY,
board.blankX + direc[0],
board.blankY + direc[1]);
if (success) {
result.enqueue(board);
}
}
return result;
}
/**
* Returns the keys in the BST in level order (for debugging).
*
* @return the keys in the BST in level order traversal
*/
private Iterable<Point2D> levelOrder() {
Queue<Point2D> keys = new Queue<Point2D>();
Queue<Node> queue = new Queue<Node>();
queue.enqueue(root);
while (!queue.isEmpty()) {
Node x = queue.dequeue();
if (x == null) {
continue;
}
keys.enqueue(x.key);
queue.enqueue(x.left);
queue.enqueue(x.right);
}
return keys;
}
public LazyPrimMST(EdgeWeightedGraph G) {
pq = new MinPQ<Edge>(G.E());
mst = new Queue<Edge>();
marked = new boolean[G.V()];
visit(G, 0);
while (!pq.isEmpty()) {
Edge e = pq.delMin();
int v = e.either();
int w = e.other(v);
if (marked[v] && marked[w]) continue;
mst.enqueue(e);
if (!marked[v]) visit(G, v);
else visit(G, w);
}
}
private void range(
final Node node, final RectHV rect, final Queue<Point2D> ranged, final boolean vertical) {
if (node == null) {
return;
}
if (rect.contains(node.key)) {
ranged.enqueue(node.key);
range(node.left, rect, ranged, !vertical);
range(node.right, rect, ranged, !vertical);
} else {
if (onTheLeft(node.key, rect, vertical)) {
range(node.left, rect, ranged, !vertical);
} else if (onTheRight(node.key, rect, vertical)) {
range(node.right, rect, ranged, !vertical);
} else {
range(node.left, rect, ranged, !vertical);
range(node.right, rect, ranged, !vertical);
}
}
}