Try out some corner cases like complete graphs, etc. Does your algorithm return 1 for a complete graph?
On Mon, May 2, 2011 at 9:09 PM, prajay shetty <[email protected]>wrote: > thanks for the admin coorporation please post the problem > > > On Mon, May 2, 2011 at 8:19 PM, prajay shetty <[email protected]>wrote: > >> >> Hey all, >> >> Last week i was going trough corfment this is not a gcj problem but i had >> wrote an algorithm on np complete that is an independent set problem which >> has no cycle and no weight i had tried this algorithm on this type of graphs >> , can anyone provied me with counter example if any ,I taught this was the >> good one comunicate with you members since most of you will be good at DSA >> atleast more than me ): thanks for any help in the problem >> >> so here is our graph which has following properties as an example >> 1) node 1 is connected to node 2 >> 2) node 2 is connected to node 3 >> 3) node 3 is connected to node 1 >> 4)node 2 is connected to node 5 >> 5) node 2 is connected to node 4 >> 6) node 5 is connectd to node 6 >> 7)node 4 is connected to node 5 >> 8) node 3 is connected to node 7 >> 9) node 7 is connected to node 8 >> 10) node 8 is connected to node 3 >> >> >> First by seeing the graph we have independent set is 1,4,6,8 >> Algorithm >> >> 1)We genearte dfs on graph g >> 2) We genearte bfs on g >> 3)DFS: here we modify our dfs a bit insteda as we go through dfs we color >> first node as blue and we dont color the next node and we color the next >> node blue this continues till we reach a dead end.,we list all the node >> that we marked as blue. >> for example we get the output as 1,3,5 now we explore 3 and we dont >> color 7 and then we color 8 like this we procceed, output is 1,3,4,6,8 >> 4) BFS: we generate bfs, then once we got the list of nodes we maintain a >> pair node in an array as parent child in our array for example we store >> 1->2,3 and 2->4,5 and 3->7,8 for bfs we can just reduce the memory space by >> working on efficient ds on this. >> 5) then we color all the node as yellow in our bfs tree for the nodes that >> we obtain in step 3 >> 6)now we check if the node that is in the list has a node connected to >> it colored as yellow ,if yes we delete it from our final list and in this >> way we get we remove 3 as 3 is connected to 1 >> so we get our final list as 1,4,6,8 >> >> just want to check if there is any counter example for this ...thanks for >> your help >> >> >> Note: step 3 can be done with step 1 and step 2 can be done with step 4 >> >> >> -- >> Regards ,Prajay >> > > > > -- > Regards ,Prajay > > -- > You received this message because you are subscribed to the Google Groups > "google-codejam" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/google-code?hl=en. > -- Rahul Gulati [email protected] Department of Computer Science Jaypee Institute of Information Technology (Deemed University) India -- You received this message because you are subscribed to the Google Groups "google-codejam" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-code?hl=en.
