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=ham autolearn_force=no version=3.4.4 X-Google-Thread: a07f3367d7,a9916530bf157e77 X-Google-Attributes: gida07f3367d7,public,usenet X-Google-NewGroupId: yes X-Google-Language: ENGLISH,ASCII-7-bit X-Received: by 10.224.160.65 with SMTP id m1mr34350438qax.2.1367080495755; Sat, 27 Apr 2013 09:34:55 -0700 (PDT) X-Received: by 10.50.12.227 with SMTP id b3mr847909igc.13.1367080495720; Sat, 27 Apr 2013 09:34:55 -0700 (PDT) Path: ef9ni27001qab.0!nntp.google.com!s14no146704qam.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Sat, 27 Apr 2013 09:34:55 -0700 (PDT) In-Reply-To: Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=69.20.190.126; posting-account=lJ3JNwoAAAAQfH3VV9vttJLkThaxtTfC NNTP-Posting-Host: 69.20.190.126 References: <87c89205-7fee-4d88-b4ab-08d26c03219b@googlegroups.com> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: <99d9a17c-ed8d-4c28-90d0-6543b511cb87@googlegroups.com> Subject: Re: Depth First Search of a Char_Matrix? From: Shark8 Injection-Date: Sat, 27 Apr 2013 16:34:55 +0000 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Date: 2013-04-27T09:34:55-07:00 List-Id: On Saturday, April 27, 2013 10:27:23 AM UTC-6, Alex wrote: > On Saturday, April 27, 2013 10:09:10 AM UTC-4, Alex wrote: >=20 > > Below is Char_Matrix representation of the board game "Go". A 'W' repr= esents a white piece, a 'B' represents a black piece, and a '.' represents = a empty space. Each black or white piece can either be alive or dead. A p= iece is Alive is if it horizontally or vertically next to a '.' OR if it is= horizontally or vertically next to another piece that is alive. You can th= ink 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 > > WW.BB >=20 > >=20 >=20 > > .WWWW >=20 > >=20 >=20 > > WWBBB >=20 > >=20 >=20 > > BBBWW >=20 > >=20 >=20 > > WWBW. >=20 > >=20 >=20 > >=20 >=20 > >=20 >=20 > >=20 >=20 > >=20 >=20 > > In this example there are 11 alive white piece and 2 alive black pieces= . >=20 > >=20 >=20 > >=20 >=20 > >=20 >=20 > > Can anyone provide any insight into this problem? >=20 >=20 >=20 > Shark you are correct, I forgot to include the fact that only like color= s are contagious. Thank you very much for your assistance. Without provid= ing the code how would I change it to reflect this piece of missing logic? Simple: 1 ) Add a local variable indicating the color to Is_Alive, that will be ac= cessable to its nested functions. 2 ) After checking for null on (x,y) assign that to the variable before ca= lling recursion. You could also make that variable a constant and use a conditional expressi= on [in Ada 2012] to set the initial value -- something like: Color : Constant Piece_Color:=3D (if board(x,y) /=3D null then board(x,y).c= olor else white); -- DEFAULT to white on NULL, otherwise set to the initial= piece's color.