priority-queue

Since both std::priority_queue and std::set (and std::multiset ) are data containers that store elements and allow you to access them in an ordered fashion, and have same insertion complexity O(log n) , what are the advantages of using one over the other (or, what kind of situations call for the one or the other?)? While I know that the underlying structures are different, I am not as much interested in the difference in their implementation as I am in the comparison their performance and suitability for various uses. Note: I know about the no-duplicates in a set. That's why I also mentioned

The default stl priority queue is a Max one (Top function returns the largest element). Say, for simplicity, that it is a priority queue of int values. Use std::greater as the comparison function: std::priority_queue<int, std::vector<int>, std::greater<int> > my_min_heap; One way would be to define a suitable comparator with which to operate on the ordinary priority queue, such that its priority gets reversed: #include <iostream> #include <queue> using namespace std; struct compare { bool operator()(const int& l, const int& r) { return l > r; } }; int main() { priority_queue<int,vector<int>,

i am very confused with this little example of java.util.PriorityQueue and my own Comparator: In this code i get a wrong order in the queue. The result is: 5,8,7 instead of 5,7,8 Is there anything wrong with my Comparator<Vertex> ? Thank you for your help. public class Test { public static void main(String[] args) { PriorityQueue<Vertex> priorityQueue = new PriorityQueue<Vertex>(new Comparator() { @Override public int compare(Object o1, Object o2) { Vertex u = (Vertex) o1; Vertex v = (Vertex) o2; return Integer.compare(new Integer(u.distance), new Integer(v.distance)); } }); Vertex vertex1 =

I would like to build a priority queue in python in which the queue contains different dictionaries with their priority numbers. So when a "get function" is called, the dictionary with the highest priority(lowest number) will be pulled out of the queue and when "add function" is called, the new dictionary will be added to the queue and sorted based on its priority number. Please do help out... Thanks in advance! Use the heapq module in the standard library. You don't specify how you wanted to associate priorities with dictionaries, but here's a simple implementation: import heapq class

On the wave of this SO question and with many hints from another one , I'm trying to implement an AsyncTask variant with tasks that can be prioritized. In my CustomAsyncTask class I have: public abstract class CustomAsyncTask<Params, Progress, Result> { private static int CORE_POOL_SIZE = 1; private static int MAXIMUM_POOL_SIZE = 1; private static final int KEEP_ALIVE = 1; private static final ThreadFactory sThreadFactory = new ThreadFactory() { private final AtomicInteger mCount = new AtomicInteger(1); public Thread newThread(Runnable r) { return new Thread(r, "CustomAsyncTask #" + mCount