priority-queue

问题 I want a data structure with priority queue functions in O(logn) time and also be able to delete a specific element that's not necessarily the head in O(logn) time. I heard the TreeSet in java does it but does not allow Duplicates, How do i get around this? 回答1: Use TreeMap which allows insertion in log n time and deletion in log n time. You can have there TreeMap<Integer,Integer> where key stores the value of element and value stores the frequency of the element. If you need to do only

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 4 years ago . Consider the following code: import java.util.PriorityQueue; public class Test { public static void main(String argv[]) { PriorityQueue<A> queue = new PriorityQueue<>(); System.out.println("Size of queue is " + queue.size()); // prints 0 try { queue.add(new A()); } catch (ClassCastException ignored) { } System

问题 I am implementing Abstract Data Type - Priority que, but I can't find out how to put values in correct order. My structures: typedef int kintyr; typedef struct qElem { struct qElem *prv; kintyr *dat; int *priority; }qElem; typedef struct que { qElem *fr,*bk; int cnt; }que; And now my main functions to implement a Priority que First to create an empty PQ: que *qNew() { que *q = malloc(sizeof(*q)); if (q==NULL) return NULL; q->fr = NULL; q->bk = NULL; q->cnt = 0; qFault = 0; return q; } This is

问题 When I run the following priority queue test: class Run { public static void main(String[] args) { PriorityQueue<Entry> q = new PriorityQueue<>(8, Collections.reverseOrder(new Comparator<Entry>() { @Override public int compare(Entry o1, Entry o2) { return Integer.compare(o1.getValue(), o2.getValue()); } })); q.offer(new Entry(100)); q.offer(new Entry(0)); q.offer(new Entry(1)); q.offer(new Entry(-1)); q.offer(new Entry(0)); q.offer(new Entry(1)); q.offer(new Entry(-100)); q.offer(new Entry

问题 Suppose that I have a priority queue which removes elements in increasing order, and stored in this queue are the elements 1, 1, 3, 0, 1 . The increasing order is 0 then 1 then 3 , but there are three element 1 s. When I call remove it will first remove the 0 , but if I call remove again will it remove all three 1 s at the same time, or will I need to call remove three separate times to remove all of the 1 elements. Does a call to remove on such a priority queue remove all elements of the

问题 Even though this question sounds as a duplicate, I searched a lot but couldn't find a proper solution. I have following classes public enum ChangeType { Add, Modify, Delete } public enum ChangedObjectType { Project, Customer, Border, Photo } public struct ChangeInfo { public ChangeType typeofChange { get; private set; } public ChangedObjectType objectType { get; private set; } public string objectID { get; private set; } public ChangeInfo(ChangeType changeType, ChangedObjectType changeObj,

问题 I'd like to get a code sample that accomplishes ascending ordering of items in a priority queue. I'd like to store Tuple2(Int, String) inside a priority queue so that it is ordered by the first element of the tuple in ascending order. If my priority queue is called pq and I call pq.head I'd like to get the tuple with the lowest number, same thing with calling pq.dequeue . scala> val pq = scala.collection.mutable.PriorityQueue[(Int, String)]() pq: scala.collection.mutable.PriorityQueue[(Int,

问题 In my implementation of Dijkstra's algorithm I have 1 array with all nodes and 1 priority queue with all nodes. Whenever a node is dequeued I update all adjacent nodes with new distance and where it came from, so I can backtrack the path. The node in the priority queue is updated with new distance and the node in the array is updated where it came from and with new distance. When a node is dequeued the final distance in the array is updated: PathInfo current = pq.remove(); path[current.pos]

问题 Is there a concurrent mutable priority queue? Ideally, I'm looking for a C++ implementation, but, for starters, a pointer to an algorithm would be very helpful. To be clear, I'm looking for a priority queue where I can adjust the priorities of the elements. In particular, TBB's concurrent_priority_queue doesn't provide the necessary functionality. (For that matter, neither does STL's priority_queue , even if we ignore the concurrency.) Boost.Heap library provides serial functionality that I

问题 I'm trying to get RabbitMQ working in a multi-queue, message priority scenario. However, while I'm setting the job's priority correctly, the worker processes are not respecting the priority set in the message. Task runner: require_once __DIR__ . '/vendor/autoload.php'; use PhpAmqpLib\Connection\AMQPConnection; use PhpAmqpLib\Message\AMQPMessage; $connection = new AMQPConnection('localhost', 5672, 'guest', 'guest'); $channel = $connection->channel(); $channel->queue_declare('task_queue', false