Account Options

  1. Sign in
The old Google Groups will be going away soon, but your browser is incompatible with the new version.
Google Groups Home
« Groups Home
Converting an adjacency list into partitioning..help needed
There are currently too many topics in this group that display first. To make this topic appear first, remove this option from another topic.
There was an error processing your request. Please try again.
flag
  5 messages - Collapse all  -  Translate all to Translated (View all originals)
The group you are posting to is a Usenet group. Messages posted to this group will make your email address visible to anyone on the Internet.
Your reply message has not been sent.
Your post was successful
 
From:
To:
Cc:
Followup To:
Add Cc | Add Followup-to | Edit Subject
Subject:
Validation:
For verification purposes please type the characters you see in the picture below or the numbers you hear by clicking the accessibility icon. Listen and type the numbers you hear
 
Karthik  
View profile  
 More options Oct 11 2005, 2:51 am
From: "Karthik" <kjkar...@gmail.com>
Date: Mon, 10 Oct 2005 23:51:58 -0700
Local: Tues, Oct 11 2005 2:51 am
Subject: Converting an adjacency list into partitioning..help needed
HI guys,

     I have encountered a problem on converting an adjacency matrix
into partitioning. By partitioning, I mean that they are a collection
of lists in which order and connectivity within a list doesnt
matter..For ex:

Input:
------
  A B C D E F
A 0 1 0 0 0 1
B 1 0 0 0 0 0
C 0 0 0 1 0 0
D 0 0 1 0 1 0
E 0 0 0 1 0 0
F 1 0 0 0 0 0

Distinct Pairs : (A,B),(A,F),(C,D),(D,E)

Hence the output shd be :  (A,B,F)
          ------           (C,D,E)       2 lists

The matrix is essentially a symmetric square matrix in which diagonal
elements are irrelevant.So, only (((N^2)/2) - N) are only stored to
reduce memory.

   I have thought of an algorithm doing this job in O(N^3) time and
O(N) in space. Can any suggest me an algorithm better than this
complexity. N is very large for me, so I cant afford O(N^3)..Please
help..


 
You must Sign in before you can post messages.
To post a message you must first join this group.
Please update your nickname on the subscription settings page before posting.
You do not have the permission required to post.
Andy Twigg  
View profile  
 More options Oct 11 2005, 5:44 am
From: "Andy Twigg" <andy.tw...@gmail.com>
Date: Tue, 11 Oct 2005 09:44:07 -0000
Local: Tues, Oct 11 2005 5:44 am
Subject: Re: Converting an adjacency list into partitioning..help needed
Why not just use time O(n^2) to construct the connected components of
the graph? This is what you appear to want from your output.

-Andy


 
You must Sign in before you can post messages.
To post a message you must first join this group.
Please update your nickname on the subscription settings page before posting.
You do not have the permission required to post.
Karthik  
View profile  
 More options Oct 11 2005, 9:28 am
From: "Karthik" <kjkar...@gmail.com>
Date: Tue, 11 Oct 2005 06:28:17 -0700
Local: Tues, Oct 11 2005 9:28 am
Subject: Re: Converting an adjacency list into partitioning..help needed
I just didnt get ur point really...I want to say that here in the
problem you are not given the pairs, You are only provided with the
square matrix from where you shd derive the lists...Do u want to say
that it is still possible in a O(N^2) time?? If so plz explain..

 
You must Sign in before you can post messages.
To post a message you must first join this group.
Please update your nickname on the subscription settings page before posting.
You do not have the permission required to post.
Karthik  
View profile  
 More options Oct 12 2005, 2:06 am
From: "Karthik" <kjkar...@gmail.com>
Date: Tue, 11 Oct 2005 23:06:15 -0700
Local: Wed, Oct 12 2005 2:06 am
Subject: Re: Converting an adjacency list into partitioning..help needed
Can u just describe or send a link to the algorithm which converts
matrix into graph in O(N^2) time.....

 
You must Sign in before you can post messages.
To post a message you must first join this group.
Please update your nickname on the subscription settings page before posting.
You do not have the permission required to post.
Andy Twigg  
View profile  
 More options Oct 13 2005, 7:21 am
From: "Andy Twigg" <andy.tw...@gmail.com>
Date: Thu, 13 Oct 2005 11:21:06 -0000
Local: Thurs, Oct 13 2005 7:21 am
Subject: Re: Converting an adjacency list into partitioning..help needed
Doesn't the matrix represent the graph? It is just the adjacency matrix
of the graph..

 
You must Sign in before you can post messages.
To post a message you must first join this group.
Please update your nickname on the subscription settings page before posting.
You do not have the permission required to post.
End of messages
« Back to Discussions « Newer topic     Older topic »