You can order the envelopes by area!
Wladimir Araujo Tavares http://www.si.ufc.br/~wladimir <http://www.si.ufc.br/%7Ewladimir/> "Fiz uma faculdade! Só não fiz a segunda porque acabaram os tijolos." On Tue, Oct 19, 2010 at 11:23 AM, Wladimir Tavares <wladimir...@gmail.com>wrote: > This problem is a variation of Longest Increasing Subsequence (LIS). The > faster algorithm é O(n log n) > > http://en.wikipedia.org/wiki/Longest_increasing_subsequence > > http://www.algorithmist.com/index.php/Longest_Increasing_Subsequence > > > Wladimir Araujo Tavares > http://www.si.ufc.br/~wladimir <http://www.si.ufc.br/%7Ewladimir/> > "Fiz uma faculdade! Só não fiz a segunda porque acabaram os tijolos." > > > > > > On Mon, Oct 18, 2010 at 7:53 PM, Marcelo Amorim Menegali < > mmeneg...@gmail.com> wrote: > >> The problem statement doesn't make it clear, but I guess one can rotate >> the envelopes (i.e. exchange x_i and y_i). >> I mean, in the example case of {(1,2),(2,13),(5,10),(7,9),(9,1)}, isn't >> (1,2),(1,9),(5,10) a valid solution (with length 3), instead of the ones >> shown (with length 2)? >> >> >> On Sat, Oct 16, 2010 at 5:40 PM, nishaanth <nishaant...@gmail.com> wrote: >> >>> ya...finding the longest subsequence is the simplest method...and its >>> nlogn.. >>> >>> It works...it similar to box stacking problem >>> >>> >>> On Fri, Oct 1, 2010 at 6:00 AM, adit.sh...@gmail.com < >>> adit.sh...@gmail.com> wrote: >>> >>>> The problem here is more about finding the most optimal solution and not >>>> just solution. >>>> Rgds >>>> Adi >>>> -----Original Message----- >>>> From: Sathaiah Dontula >>>> Sent: 29/09/2010, 09:25 >>>> To: algogeeks@googlegroups.com >>>> Subject: Re: [algogeeks] Algorithm to determine the largest number of >>>> envelopes that can be nested inside one another. >>>> >>>> >>>> I think we can do like this, >>>> >>>> 1. Sort all the xi's in ascending order -> nlog(n) >>>> 2. Then find the longest increasing sequence of yi's -> nlog(n) >>>> 3. complexity will be nlog(n). >>>> >>>> Thanks, >>>> Sathaiah Dontula >>>> >>>> On Tue, Sep 28, 2010 at 11:37 PM, Prashant Kulkarni < >>>> prashant.r.k...@gmail.com> wrote: >>>> >>>> > i think it is similar to finding max in a list O(n) or sorting >>>> algorithm >>>> > O(n log n) >>>> > >>>> > -- Prashant Kulkarni >>>> > >>>> > >>>> > >>>> > >>>> > On Tue, Sep 28, 2010 at 11:33 PM, Rahul Singal < >>>> rahulsinga...@gmail.com>wrote: >>>> > >>>> >> A possible solution i can think is create a directed graph where >>>> each >>>> >> vertex is a envelope and edges are from a bigger envelope to smaller >>>> >> envelope ( one which can fit in bigger envelope ) . Now the problem >>>> is >>>> >> reduce to finding longest path in the graph . >>>> >> >>>> >> Regards >>>> >> Rahul >>>> >> >>>> >> -- >>>> >> You received this message because you are subscribed to the Google >>>> Groups >>>> >> "Algorithm Geeks" group. >>>> >> To post to this group, send email to algoge...@googlegroups.com. >>>> >> To unsubscribe from this group, send email to >>>> >> algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> >>>> <algogeeks%2bunsubscr...@googlegroups.com<algogeeks%252bunsubscr...@googlegroups.com> >>>> > >>>> >> . >>>> >> For more options, visit this group at >>>> >> http://groups.google.com/group/algogeeks?hl=en. >>>> >> >>>> > >>>> > -- >>>> > You received this message because you are subscribed to the Google >>>> Groups >>>> > "Algorithm Geeks" group. >>>> > To post to this group, send email to algoge...@googlegroups.com. >>>> > To unsubscribe from this group, send email to >>>> > algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> >>>> <algogeeks%2bunsubscr...@googlegroups.com<algogeeks%252bunsubscr...@googlegroups.com> >>>> > >>>> > . >>>> > For more options, visit this group at >>>> > http://groups.google.com/group/algogeeks?hl=en. >>>> > >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Algorithm Geeks" group. >>>> To post to this group, send email to algoge...@googlegroups.com. >>>> To unsubscribe from this group, send email to >>>> algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> >>>> . >>>> For more options, visit this group at >>>> http://groups.google.com/group/algogeeks?hl=en. >>>> >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Algorithm Geeks" group. >>>> To post to this group, send email to algoge...@googlegroups.com. >>>> To unsubscribe from this group, send email to >>>> algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> >>>> . >>>> For more options, visit this group at >>>> http://groups.google.com/group/algogeeks?hl=en. >>>> >>>> >>> >>> >>> -- >>> S.Nishaanth, >>> Computer Science and engineering, >>> IIT Madras. >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "Algorithm Geeks" group. >>> To post to this group, send email to algoge...@googlegroups.com. >>> To unsubscribe from this group, send email to >>> algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> >>> . >>> For more options, visit this group at >>> http://groups.google.com/group/algogeeks?hl=en. >>> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Algorithm Geeks" group. >> To post to this group, send email to algoge...@googlegroups.com. >> To unsubscribe from this group, send email to >> algogeeks+unsubscr...@googlegroups.com<algogeeks%2bunsubscr...@googlegroups.com> >> . >> For more options, visit this group at >> http://groups.google.com/group/algogeeks?hl=en. >> > > -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. 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