Databases
StackOverflow2013
Postsdbo
POhelp in the Donalds B. Johnson's algorithm, i cannot understand the pseudo code (PART II)
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POhelp in the Donalds B. Johnson's algorithm, i cannot understand the pseudo code (PART II)
    primarykey
    data
    text
    <p>i cannot understand a certain part of the paper published by Donald Johnson about finding cycles (Circuits) in a graph.</p> <p>More specific i cannot understand what is the matrix Ak which is mentioned in the following line of the pseudo code :</p> <p>Ak:=adjacency structure of strong component K with least vertex in subgraph of G induced by {s,s+1,....n};</p> <p>to make things worse some lines after is mentins " for i in Vk do " without declaring what the Vk is...</p> <p>As far i have understand we have the following: 1) in general, a strong component is a sub-graph of a graph, in which for every node of this sub-graph there is a path to any node of the sub-graph (in other words you can access any node of the sub-graph from any other node of the sub-graph)</p> <p>2) a sub-graph <b>induced </b> by a list of nodes is a graph containing all these nodes plus all the edges connecting these nodes. in paper the mathematical definition is " F is a subgraph of G induced by W if W is subset of V and F = (W,{u,y)|u,y in W and (u,y) in E)}) where u,y are edges , E is the set of all the edges in the graph, W is a set of nodes.</p> <p>3)in the code implementation the nodes are named by integer numbers 1 ... n. </p> <p>4) I <b>suspect</b> that the Vk is the set of nodes of the strong component K.</p> <p>now to the question. Lets say we have a graph G= (V,E) with V = {1,2,3,4,5,6,7,8,9} which it can be divided into 3 strong components the SC1 = {1,4,7,8} SC2= {2,3,9} SC3 = {5,6} (and their edges)</p> <p>Can anybody give me an example for s =1, s= 2, s= 5 what if going to be the Vk and Ak according to the code?</p> <p>The pseudo code is in my previous question in <a href="https://stackoverflow.com/questions/2908575/help-in-the-donalds-b-johnsons-algorithm-i-cannot-understand-the-pseudo-code">Understanding the pseudocode in the Donald B. Johnson&#39;s algorithm</a></p> <p>and the paper can be found at <a href="https://stackoverflow.com/questions/2908575/help-in-the-donalds-b-johnsons-algorithm-i-cannot-understand-the-pseudo-code">Understanding the pseudocode in the Donald B. Johnson&#39;s algorithm</a></p> <p>thank you in advance</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USCommunity
    1. USPitelk
    plurals
    1. PL
      singulars
      1. LTLinked
    2. PL
      singulars
      1. LTLinked
    1. PL
      singulars
      1. LTLinked
    2. PL
      singulars
      1. LTLinked
    3. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POhelp in the Donalds B. Johnson's algorithm, i cannot understand the pseudo code (PART II)
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POhelp in the Donalds B. Johnson's algorithm, i cannot understand the pseudo code (PART II)
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POhelp in the Donalds B. Johnson's algorithm, i cannot understand the pseudo code (PART II)
      1. This table or related slice is empty.
      1. VTUpMod
    1. This table or related slice is empty.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload