From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM autolearn=unavailable autolearn_force=no version=3.4.4 X-Received: by 10.224.58.77 with SMTP id f13mr34376465qah.7.1367081721909; Sat, 27 Apr 2013 09:55:21 -0700 (PDT) X-Received: by 10.49.95.231 with SMTP id dn7mr4108274qeb.39.1367081721887; Sat, 27 Apr 2013 09:55:21 -0700 (PDT) Path: border1.nntp.dca3.giganews.com!border3.nntp.dca.giganews.com!border1.nntp.dca.giganews.com!nntp.giganews.com!s14no155604qam.0!news-out.google.com!ef9ni27001qab.0!nntp.google.com!s14no156116qam.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Sat, 27 Apr 2013 09:55:21 -0700 (PDT) In-Reply-To: <4c3eca49-8ee6-4518-9968-879c08b828f6@googlegroups.com> Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=134.240.94.19; posting-account=CZZpzgoAAAAoaHoNNp9zhY9EzQgEmxhU NNTP-Posting-Host: 134.240.94.19 References: <87c89205-7fee-4d88-b4ab-08d26c03219b@googlegroups.com> <99d9a17c-ed8d-4c28-90d0-6543b511cb87@googlegroups.com> <4c3eca49-8ee6-4518-9968-879c08b828f6@googlegroups.com> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: Subject: Re: Depth First Search of a Char_Matrix? From: Alex Injection-Date: Sat, 27 Apr 2013 16:55:21 +0000 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Original-Bytes: 5595 Xref: number.nntp.dca.giganews.com comp.lang.ada:181243 Date: 2013-04-27T09:55:21-07:00 List-Id: On Saturday, April 27, 2013 12:51:44 PM UTC-4, Alex wrote: > On Saturday, April 27, 2013 12:34:55 PM UTC-4, Shark8 wrote: >=20 > > On Saturday, April 27, 2013 10:27:23 AM UTC-6, Alex wrote: >=20 > >=20 >=20 > > > On Saturday, April 27, 2013 10:09:10 AM UTC-4, Alex wrote: >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > > Below is Char_Matrix representation of the board game "Go". A 'W' = represents a white piece, a 'B' represents a black piece, and a '.' represe= nts a empty space. Each black or white piece can either be alive or dead. = A piece is Alive is if it horizontally or vertically next to a '.' OR if i= t is horizontally or vertically next to another piece that is alive. You ca= n think of aliveness as being contagious. How can I use depth first search= to count the number of alive black pieces and alive white pieces? =20 >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > >=20 >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > >=20 >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > >=20 >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > > WW.BB >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > >=20 >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > > .WWWW >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > >=20 >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > > WWBBB >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > >=20 >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > > BBBWW >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > >=20 >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > > WWBW. >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > >=20 >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > >=20 >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > >=20 >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > >=20 >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > >=20 >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > > In this example there are 11 alive white piece and 2 alive black pi= eces. >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > >=20 >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > >=20 >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > >=20 >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > > Can anyone provide any insight into this problem? >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > >=20 >=20 > >=20 >=20 > > > Shark you are correct, I forgot to include the fact that only like c= olors are contagious. Thank you very much for your assistance. Without pr= oviding the code how would I change it to reflect this piece of missing log= ic? >=20 > >=20 >=20 > >=20 >=20 > >=20 >=20 > > Simple: >=20 > >=20 >=20 > > 1 ) Add a local variable indicating the color to Is_Alive, that will b= e accessable to its nested functions. >=20 > >=20 >=20 > > 2 ) After checking for null on (x,y) assign that to the variable befor= e calling recursion. >=20 > >=20 >=20 > >=20 >=20 > >=20 >=20 > > You could also make that variable a constant and use a conditional expr= ession [in Ada 2012] to set the initial value -- something like: >=20 > >=20 >=20 > > Color : Constant Piece_Color:=3D (if board(x,y) /=3D null then board(x,= y).color else white); -- DEFAULT to white on NULL, otherwise set to the ini= tial piece's color. >=20 >=20 >=20 > Thanks! So I am given the function signature, not really a function body = that looks like this >=20 >=20 >=20 > function Count_Alive(Board : Char_Matrix) return Integer is >=20 > M : Char_Matrix :=3D Board; =20 >=20 > begin >=20 > return -999; >=20 > end Count_Alive; >=20 >=20 >=20 >=20 >=20 > So I understand much of your logic, but I am given a matrix of characters= defined as such: >=20 >=20 >=20 > type Char_Matrix is array(Positive range <>, Positive range <>) of Charac= ter; >=20 >=20 >=20 > So could you give me like an algorithm in words on what I need to do inst= ead of giving me the answer in code? The characters are just like the original example: either a 'B' a 'W' or a = '.' ('.' is empty space, not null)