Thanks everyone for suggested solutions to-date... I'm not holding up the show for this any longer. Chris has a virtually complete ms in his hands, containing "good enough" answers, and I want to go to press before Christmas. So I've created a discussion page and will publish a link to it in the book: http://www.jsoftware.com/jwiki/Doc/Articles/AnswersToAPWJ This just serves as a focal point: suggested solutions are going to be appended to the articles themselves.
It was always the intention that the Wiki version of APWJ would live on after Edn 2 was published, growing all the time as discussions were appended. Here's the first instance of this. Ian Clark Subeditor, APWJ Edn 2. On Tue, Nov 24, 2009 at 2:02 AM, Chris Burke <cbu...@jsoftware.com> wrote: > Just following up on Ian's recent messages, see below. > > Ian tells me the only major items outstanding for publishing the second > edition are these two questions. > > Any help on them would be much appreciated, thanks. > > > -------- Original Message -------- > Subject: Re: [Jprogramming] APWJ exercises for the reader [3 of 4] > Date: Thu, 19 Nov 2009 03:56:05 +0000 > From: Ian Clark <earthspo...@googlemail.com> > Reply-To: Programming forum <programming@jsoftware.com> > To: Programming forum <programming@jsoftware.com> > References: <45319e520911110355r6b78ebd2paec3ebeb2cb8d...@mail.gmail.com> > > Almost ready to publish APWJ Edn. Just need answers to these 2 > problems, [3 of 4] and [4 of 4]. > > Ian > > > On Wed, Nov 11, 2009 at 11:55 AM, Ian Clark <earthspo...@googlemail.com> > wrote: >> In At Play With J Edn 1, there were 4 questions left as exercises for >> the reader. In Edn 2 we want to provide the answers in an Appendix. >> >> Just so I don't get them wrong, could the forum please suggest what >> the answers should be? You may have to refer to the Wiki page. >> >> I'm putting each question in a separate thread. >> >> +++++ >> In: Ch 23 An Open and Shut Case >> http://www.jsoftware.com/jwiki/Doc/Articles/Play164 [see end-of-page] >> >> "Here are the rest of the questions Amy had to answer. See if you can >> answer them. >> A. What do you notice about the lockers that were touched by >> exactly two students? (Try m19 >: 2=dc ) >> B. What do you notice about the lockers that were touched by >> exactly three students? >> C. What do you notice about the lockers that were touched by >> exactly four students? >> D. What was the first locker touched by both student 6 and student 8? >> E. What do you notice about the student numbers of the students >> that touched both locker 24 and locker 36? >> F. Which students touched both locker 100 and 120? What do you >> notice about their student numbers?" >> +++++ >> >> Ian Clark >> Subeditor, APWJ Edn 2 >> > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > > > -------- Original Message -------- > Subject: Re: [Jprogramming] APWJ exercises for the reader [4 of 4] > Date: Thu, 19 Nov 2009 03:54:38 +0000 > From: Ian Clark <earthspo...@googlemail.com> > Reply-To: Programming forum <programming@jsoftware.com> > To: Programming forum <programming@jsoftware.com> > References: <45319e520911110356p50df3c4bye05e039b70bb...@mail.gmail.com> > > Almost ready to publish APWJ Edn. Just need answers to these 2 > problems, [3 of 4] and [4 of 4]. > > Ian > > > On Wed, Nov 11, 2009 at 11:56 AM, Ian Clark <earthspo...@googlemail.com> > wrote: >> In At Play With J Edn 1, there were 4 questions left as exercises for >> the reader. In Edn 2 we want to provide the answers in an Appendix. >> >> Just so I don't get them wrong, could the forum please suggest what >> the answers should be? You may have to refer to the Wiki page. >> >> I'm putting each question in a separate thread. >> >> +++++ >> in: Ch 38 The Google Test >> http://www.jsoftware.com/jwiki/Doc/Articles/Play211 [see end-of-page] >> >> Problem 2: Finding the sixth in a series >> >> You are given five 10-digit numbers from the digits of pi, and must >> find the sixth. Here are the numbers: >> >> 4338327950 >> 2795028841 >> 6939937510 >> 3993751058 >> 2110555964 >> >> Here they are, embedded in pi: >> >> 7 30 $ w >> 31415926535897932384626<4338327 >> 95028841>971<693993751058>2097494 >> 459230781640628620899862803482 >> 534211706798214808651328230664 >> 709384460955058223172535940812 >> 84811174502841027019385<2110555 >> 964>462294895493038196442881097 >> >> The first and second overlap, as do the third and fourth. >> >> I'll give two hints, the second vacuous: >> >> Hint 1: Primarily, the sixth number has three doublets and overlaps > the fifth. >> >> Hint 2: Alternately, something for nothing. >> +++++ >> >> >> Ian Clark >> Subeditor, APWJ Edn 2 >> > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
