private List<Board> solve(Board initial) {
Board twin = initial.twin();
MinPQ<SearchNode> mainQueue = new MinPQ<>();
MinPQ<SearchNode> twinQueue = new MinPQ<>();
mainQueue.insert(new SearchNode(initial, 0, null));
twinQueue.insert(new SearchNode(twin, 0, null));
while (true) {
SearchNode mainSearch = mainQueue.delMin();
SearchNode twinSearch = twinQueue.delMin();
if (mainSearch.board.isGoal()) {
return retraceSteps(mainSearch);
}
if (twinSearch.board.isGoal()) {
return null;
}
for (Board board : mainSearch.board.neighbors()) {
SearchNode mainPrevious = mainSearch.previous;
if (mainPrevious == null || !board.equals(mainPrevious.board)) {
mainQueue.insert(new SearchNode(board, mainSearch.moves + 1, mainSearch));
}
}
for (Board board : twinSearch.board.neighbors()) {
SearchNode twinPrevious = twinSearch.previous;
if (twinPrevious == null || !board.equals(twinPrevious.board)) {
twinQueue.insert(new SearchNode(board, twinSearch.moves + 1, twinSearch));
}
}
}
}
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);
}
}
public static void main(String[] args) {
WeightedQuickUnionUF uf = new WeightedQuickUnionUF(10);
MinPQ<String> minPQ = new MinPQ<>(17, new Prob1().new myComparator());
String prob =
"F-A 16 G-A 13 B-A 3 C-B 6 H-B 5 G-B 2 C-D 12 C-I 9 C-H 1 D-I 14 J-D 8 D-E 7 J-E 17 F-G 15 G-H 4 I-H 11 I-J 10";
String[] temp = prob.trim().split("\\s+");
for (int i = 0; i < temp.length; i += 2) {
String record = temp[i] + "," + temp[i + 1];
minPQ.insert(record);
}
int sizeOfMST = 0;
while (!minPQ.isEmpty() && sizeOfMST <= 9) {
String minEdgeStr = minPQ.delMin();
String[] vertexStr = minEdgeStr.split(",")[0].split("-");
int v = vertexStr[0].charAt(0) - 'A';
int w = vertexStr[1].charAt(0) - 'A';
if (!uf.connected(v, w)) {
uf.union(v, w);
System.out.println(minEdgeStr);
sizeOfMST++;
}
}
}
public static void main(String[] args) {
int M = Integer.parseInt(args[0]);
MinPQ<Transaction> pq = new MinPQ<>(M + 1);
while (StdIn.hasNextLine()) {
pq.insert(new Transaction(StdIn.readLine()));
if (pq.size() > M) {
pq.delMin();
}
}
Stack<Transaction> stack = new Stack<Transaction>();
while (!pq.isEmpty()) stack.push(pq.delMin());
for (Transaction t : stack) StdOut.println();
}
private void visit(EdgeWeightedGraph G, int v) {
marked[v] = true;
for (Edge e : G.adj(v)) {
if (!marked[e.other(v)]) pq.insert(e);
}
}
// the sweep-line algorithm
public static void main(String[] args) {
int N = Integer.parseInt(args[0]);
int INFINITY = Integer.MAX_VALUE; // -INFINITY is second smallest integer
// generate N random h-v segments
SegmentHV[] segments = new SegmentHV[N];
for (int i = 0; i < N; i++) {
int x1 = (int) (Math.random() * 10);
int x2 = x1 + (int) (Math.random() * 3);
int y1 = (int) (Math.random() * 10);
int y2 = y1 + (int) (Math.random() * 5);
if (Math.random() < 0.5) segments[i] = new SegmentHV(x1, y1, x1, y2);
else segments[i] = new SegmentHV(x1, y1, x2, y1);
System.out.println(segments[i]);
}
System.out.println();
// create events
MinPQ<Event> pq = new MinPQ<Event>();
for (int i = 0; i < N; i++) {
if (segments[i].isVertical()) {
Event e = new Event(segments[i].x1, segments[i]);
pq.insert(e);
} else if (segments[i].isHorizontal()) {
Event e1 = new Event(segments[i].x1, segments[i]);
Event e2 = new Event(segments[i].x2, segments[i]);
pq.insert(e1);
pq.insert(e2);
}
}
// run sweep-line algorithm
RangeSearch<SegmentHV> st = new RangeSearch<SegmentHV>();
while (!pq.isEmpty()) {
Event e = pq.delMin();
int sweep = e.time;
SegmentHV segment = e.segment;
// vertical segment
if (segment.isVertical()) {
// a bit of a hack here - use infinity to handle degenerate intersections
SegmentHV seg1 = new SegmentHV(-INFINITY, segment.y1, -INFINITY, segment.y1);
SegmentHV seg2 = new SegmentHV(+INFINITY, segment.y2, +INFINITY, segment.y2);
Iterable<SegmentHV> list = st.range(seg1, seg2);
for (SegmentHV seg : list) {
System.out.println("Intersection: " + segment);
System.out.println(" " + seg);
}
}
// next event is left endpoint of horizontal h-v segment
else if (sweep == segment.x1) {
st.add(segment);
}
// next event is right endpoint of horizontal h-v segment
else if (sweep == segment.x2) {
st.remove(segment);
}
}
}
