I was wondering since the API says that the remove() function returns a boolean type, how do I grab the element's info when I remove it. That is, is it possible to do:
class Node {
int stuff;
}
PriorityQueue <Node> nodes = new PriorityQueue <Node> ();
Node temp = nodes.remove(0);
Assuming off course, that the nodes PQ has a bunch of nodes in it. Would temp node have the information of the removed node or would that not work since remove() returns a boolean
Use poll method to retrieve head element
poll() is no replacement for what he wants since it only returns the head. Whereas remove(Object o) deletes the object no matter the position in the queue.
In a Queue, you can't remove Objects by position remove(int), you can only remove by reference remove(E). Queues aren't designed for random access. (The only exception probably being LinkedList, as that implements both the List and Queue interface). Your code does not compile.
This is where it is best to read the documentation. remove(object) removes that object from the queue. Due to backward compatibility its not smart enough to tell you there is no Integers in your queue. i.e. you are trying to remove the object (Integer) 0
Instead you should use the remove() method which takes no arguments which
Retrieves and removes the head of this queue. This method differs from poll only in that it throws an exception if this queue is empty.
However, a better choice might be to use poll as it does the same thing except it return null instead of an exception when the queue is empty.
poll() is no replacement for what he wants since it only returns the head. Whereas remove(Object o) deletes the object no matter the position in the queue.
That wouldn't work, you'll end up with a compile error because you're trying to assign the primitive type boolean to a variable that contains a reference to a Node instance. If you can access the Nodes in your PriorityQueue by index, you can save a reference to the object in whichever index you want first, and then remove it.
That said, looking briefly at the API for the PriorityQueue class, it looks like your usage of remove() is incorrect as well (it takes an object, not an int).
Collectionfor the job.