• Post Reply Bookmark Topic Watch Topic
  • New Topic
programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other Pie Elite all forums
this forum made possible by our volunteer staff, including ...
Marshals:
  • Campbell Ritchie
  • Tim Cooke
  • Devaka Cooray
  • Ron McLeod
  • Jeanne Boyarsky
Sheriffs:
  • Liutauras Vilda
  • paul wheaton
  • Junilu Lacar
Saloon Keepers:
  • Tim Moores
  • Stephan van Hulst
  • Piet Souris
  • Carey Brown
  • Tim Holloway
Bartenders:
  • Martijn Verburg
  • Frits Walraven
  • Himai Minh

PriorityQueue doubt

 
Ranch Hand
Posts: 652
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hi All,
Look at the below program

class PriorityQueueTest
{
public static void main(String[] args)
{
PriorityQueue p=new PriorityQueue();
p.add(1);
p.add(2);
p.add(3);
System.out.println(p.poll());
}
}

Output : 1

According to my understanding of the poll method it removes highest element. So according to me it should remove 3 but its removing 1. Can anybody clarify my doubt?
 
Sheriff
Posts: 14691
16
Eclipse IDE VI Editor Ubuntu
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
poll()
Retrieves and removes the head of this queue, or null if this queue is empty.

And about PriorityQueue:
The head of this queue is the least element with respect to the specified ordering.

So ?
 
Nik Arora
Ranch Hand
Posts: 652
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hi satou,
I didnt get.Can you explain me in detail?
 
Ranch Hand
Posts: 447
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hey

Nik

The elements in the PriorityQueue by default natural ordering.
Means if you consider numbers it will be 1,2,3..
Even if you add 3,2,1.The order will be 1,2,3..
head element means first element.
tail means last element.
in you case your displaying first element

Thanks
Anil Kumar
 
Nik Arora
Ranch Hand
Posts: 652
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hi Anil,
So the least element gets removed when there is natural ordering and if we implement the comparator interface according to the method it gets removed am i right?
 
anil kumar
Ranch Hand
Posts: 447
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hi

nik

Yes


Thanks

Anil Kumar
 
Nik Arora
Ranch Hand
Posts: 652
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Thanks Anil
 
Ranch Hand
Posts: 125
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hi guys
To add an element to queue you need to offer method not add i guess
 
Nik Arora
Ranch Hand
Posts: 652
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hi sravanthi,
Even we can use add
 
sravanthi pulukuri
Ranch Hand
Posts: 125
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Ohhh thats ice i never knew this.Any when are you palning to take the exam??

Thanks in advance
 
He got surgery to replace his foot with a pig. He said it was because of this tiny ad:
the value of filler advertising in 2021
https://coderanch.com/t/730886/filler-advertising
reply
    Bookmark Topic Watch Topic
  • New Topic