For problem A, I converted both the dictionary and the patterns to a list of L bitmasks (one for each letter/position in the pattern). Each bitmask has the bit i with 1 if the letter 'a'+i belongs to the word or to the pattern in that position. Then, you just have to do at most L bitwise "AND" operations per comparison. This solutions runs in ~0 secs.
For B, I did a kind of Flood Fill (http://en.wikipedia.org/wiki/ Flood_fill), running from top to bottom, left to right. For C, I did the easiest Dynamic Programming (http://en.wikipedia.org/ wiki/Dynamic_programming) approach. But it's easy to optimize it (it still runs in about 0.1 secs). You may check my code. My username is mogers. I think that the problems were easier than last year's qualification round. Too bad because I could solve problems like these in the online round 1 x) On Sep 4, 9:53 am, Monang Setyawan <[email protected]> wrote: > There is contest analysis in the dashboard. > > > > On Fri, Sep 4, 2009 at 2:50 PM, Dhruva Sagar <[email protected]> wrote: > > But I don't see how I could improve my algo. > > Thanks & Regards, > > Dhruva Sagar. > > > Mike Ditka <http://www.brainyquote.com/quotes/authors/m/mike_ditka.html> - > > "If God had wanted man to play soccer, he wouldn't have given us arms." > > > On Fri, Sep 4, 2009 at 1:18 PM, Monang Setyawan <[email protected]> wrote: > > >> I think the algorithm have more impact than language choice, at least in > >> contest like this one. > > >> On Fri, Sep 4, 2009 at 2:42 PM, Dhruva Sagar <[email protected]>wrote: > > >>> For the large input, my solution did take long, but it was lesser than a > >>> minute in my knowledge. The best solutions are almost always in C/C++ > > >>> Thanks & Regards, > >>> Dhruva Sagar. > > >>> Stephen > >>> Leacock<http://www.brainyquote.com/quotes/authors/s/stephen_leacock.html> > >>> - "I detest life-insurance agents: they always argue that I shall some day > >>> die, which is not so." > > >>> On Fri, Sep 4, 2009 at 12:49 PM, Monang Setyawan <[email protected]>wrote: > > >>>> Well, I've run my old code again (which use regex) and run against some > >>>> generated large input. It took more than a minute to complete (that's > >>>> why I > >>>> consider it "failed"). The better solution run under 1 second against the > >>>> same input. > > >>>> On Fri, Sep 4, 2009 at 9:18 AM, Dhruva Sagar > >>>> <[email protected]>wrote: > > >>>>> Yes apparently my solution solved the large input file as well. > >>>>> I don't see why it shouldn't. > > >>>>> This is my solution in Ruby : (easiest programming language to > >>>>> understand IMO) > > >>>>> filename = ARGV[0] > >>>>> input = IO.readlines(filename) > >>>>> output = File.new('output', 'w') > > >>>>> L = input[0].split(' ')[0].to_i > >>>>> D = input[0].split(' ')[1].to_i > >>>>> N = input[0].split(' ')[2].to_i > > >>>>> words = [] > >>>>> testcases = [] > > >>>>> 1.upto(D) do |i| > >>>>> words[i-1] = input[i] > >>>>> end > > >>>>> (D+1).upto(D+N) do |i| > >>>>> testcases[i-D-1] = input[i] > >>>>> testcases[i-D-1] = testcases[i-D-1].gsub('(','[').gsub(')',']') > >>>>> end > > >>>>> testcases.each_with_index do |t, i| > >>>>> r = Regexp.new(t.to_s) > >>>>> count = 0 > >>>>> words.each do |w| > >>>>> count+=1 if !r.match(w).nil? > >>>>> end > >>>>> output.puts "Case ##{i+1}: #{count}\n" > >>>>> end > > >>>>> output.close > > >>>>> Thanks & Regards, > >>>>> Dhruva Sagar. > > >>>>> Charles de > >>>>> Gaulle<http://www.brainyquote.com/quotes/authors/c/charles_de_gaulle.html> > >>>>> - "The better I get to know men, the more I find myself loving dogs." > > >>>>> On Fri, Sep 4, 2009 at 7:41 AM, Monang Setyawan <[email protected]>wrote: > > >>>>>> Did your solution pass the large input? I've tried similar approach > >>>>>> first but change it to the more appropriate one, since it failed the > >>>>>> large > >>>>>> input case. > > >>>>>> On Fri, Sep 4, 2009 at 8:46 AM, Pedro Henrique Calais < > >>>>>> [email protected]> wrote: > > >>>>>>> Yes, they are available on the web site. > > >>>>>>> My solution for problem A was just to convert the words to regexs: > > >>>>>>> (ab)c(cd) --> [ab]c[cd] > > >>>>>>> and then tested the regex against all the vocabulary of the language. > > >>>>>>> -- Pedro > > >>>>>>> On Thu, Sep 3, 2009 at 10:44 PM, Dhruva Sagar < > >>>>>>> [email protected]> wrote: > > >>>>>>>> I finished only problem A for both small & large :(. > >>>>>>>> Came close to finishing B, but time ran out. > > >>>>>>>> Is it possible to see others' solutions ? I would love to. > > >>>>>>>> Thanks & Regards, > >>>>>>>> Dhruva Sagar. > > >>>>>>>> Pablo > >>>>>>>> Picasso<http://www.brainyquote.com/quotes/authors/p/pablo_picasso.html> > >>>>>>>> - "Computers are useless. They can only give you answers." > > >>>>>>>> On Fri, Sep 4, 2009 at 6:55 AM, MagicLi <[email protected]>wrote: > > >>>>>>>>> I finish problem A&B, for problem C, I finish the small input, my > >>>>>>>>> program fail the large input. I think there is better algorithm to > >>>>>>>>> work it out. > > >>>>>> -- > >>>>>> "Don't worry about what anybody else is going to do. The best way to > >>>>>> predict the future is to invent it." - Alan Kay > > >>>> -- > >>>> "Don't worry about what anybody else is going to do. The best way to > >>>> predict the future is to invent it." - Alan Kay > > >> -- > >> "Don't worry about what anybody else is going to do. The best way to > >> predict the future is to invent it." - Alan Kay > > -- > "Don't worry about what anybody else is going to do. The best way to predict > the future is to invent it." - Alan Kay --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
