priority-queue

问题 In the section that explains Dijkstra's Algorithm in the book Introduction to Algorithms by Cormen et. al., while analysing the complexity of the algorithm, they say If the graph is sufficiently sparse ... we can improve the algorithm by implementing the min priority queue with a binary min heap So I was wondering, what is the need for such a statement? Isn't it always wiser to just use heaps for priority queues? 回答1: There are many different ways to implement a priority queue. A binary min

问题 Am new to Bull.I have tried running bull based on their documentation code. The Process are starting but my job is not getting completed, or am not sure whether its triggering complete event or not? Am not sure where am making a mistake Attaching my code below const Queue = require('bull'); const myFirstQueue = new Queue('my-first-queue', { redis: { port: Config.redis.port, host: Config.redis.host, password: Config.redis.password }, }); (async function ad() { const job = await myFirstQueue

问题 I have been trying to create a priority queue in which every element is a pair that stores a pointer to an unsigned int and an unsigned int . The problem is that whenever I add a pair to the priority queue, the element that the previously added pair was pointing to, switches its value to 0. Here is the code #include <iostream> #include <vector> #include <utility> #include <queue> typedef unsigned int ui; typedef std::pair<ui*, ui> Ppuiui; typedef std::priority_queue<Ppuiui> Queue; void showPQ

问题 I am trying to utilize a PriorityQueue from the queue class. However, i'm having issues putting custom objects into my PQ. I have implemented the __cmp__ function below: def __cmp__(self, other): return (self.priority > other.priority) - (self.priority < other.priority) I want the PriorityQueue to be sorted by the priority field, as assigned in my init function: def __init__(self, board, priority=0): self.priority = priority # Other logic However, when I run the code to insert a State object

问题 I've been looking everywhere for a priority queue implementation for Common Lisp that works, and so far, I've not had much luck. As I'm fairly new to Common Lisp, whenever I see a huge warning/error dump from the REPL, I'm not really sure what to do about it. This isn't helped by the fact that all the priority queue implementations I've found seem to be really old. Could someone suggest one to me? 回答1: A quick search for "queue" on http://quickdocs.org turned up a few choices. I looked at the

问题 I have written a code that solves MST using Prim method. I read that this kind of implementation(using priority queue) should have O(E + VlogV) = O(VlogV) where E is the number of edges and V number of Edges but when I look at my code it simply doesn't look that way.I would appreciate it if someone could clear this up for me. To me it seems the running time is this: The while loop takes O(E) times(until we go through all the edges) Inside that loop we extract an element from the Q which takes

问题 I'm searching for a kind of priority queue which allows me to give two priorites. I want that it just check for the first value then for the second one Here is some Code import Queue class Job(object): def __init__(self, fpriority, spriority, description, iata , hops, cost): self.fpriority = fpriority self.spriority = spriority q = Queue.PriorityQueue() q.put(Job(2, 5, 'Mid-level job')) q.put(Job(2, 20, 'Low-level job')) q.put(Job(1, 20, 'Important job')) now i want the following order of the

问题 Been struggling with this for over 2 days now. implemented the answer I saw on here Specify task order execution in Java public class PriorityExecutor extends ThreadPoolExecutor { public PriorityExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit, BlockingQueue<Runnable> workQueue) { super(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue); } //Utitlity method to create thread pool easily public static ExecutorService newFixedThreadPool(int nThreads)

问题 I'm looking for a PriorityQueue implementation which is also a Set. The compareTo implementation if its elements must not have the requirement to be consistent with the implementation of equals . Is there somewhere such a implementation for java? Update: I implemented it now using a SortedSet as the internal collection. So I only had to implement the missing methods to satisfy the queue interface. I also forgot to mention that it also had to be a bounded queue, so it features a capacity and

问题 I wanted to implement multiprocessing priorityqueue . I found this answer :- Strange Queue.PriorityQueue behaviour with multiprocessing in Python 2.7.6 by Dano After I implemented this . I could use .get() and .put() function for my Priority Queue but when i used .queue to print the current elements in the queue it gave me an error code:- class MyManager(SyncManager): pass def get_manager(): MyManager.register("PriorityQueue", PriorityQueue) # Register a shared PriorityQueue m = MyManager() m