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=-0.6 required=5.0 tests=BAYES_00,FREEMAIL_FROM, FROM_STARTS_WITH_NUMS,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: fc89c,97188312486d4578 X-Google-Attributes: gidfc89c,public X-Google-Thread: 1014db,6154de2e240de72a X-Google-Attributes: gid1014db,public X-Google-Thread: 103376,97188312486d4578 X-Google-Attributes: gid103376,public X-Google-Thread: 109fba,baaf5f793d03d420 X-Google-Attributes: gid109fba,public From: 71101.1702@compuserve.com (Steve Heller) Subject: Re: Teaching sorts [was Re: What's the best language to start with?] Date: 1996/08/12 Message-ID: <4umeot$re2@hil-news-svc-2.compuserve.com>#1/1 X-Deja-AN: 173633462 references: <31FBC584.4188@ivic.qc.ca> <01bb83f5$923391e0$87ee6fce@timpent.airshields.com> <4uah1k$b2o@solutions.solon.com> <01bb853b$ca4c8e00$87ee6fce@timpent.airshields.com> <4udb2o$7io@solutions.solon.com> organization: CompuServe Incorporated newsgroups: comp.lang.c,comp.lang.c++,comp.unix.programmer,comp.lang.ada Date: 1996-08-12T00:00:00+00:00 List-Id: eachus@spectre.mitre.org (Robert I. Eachus) wrote: > My favorite way to teach sorts is with cards. You can use playing >cards, but a set of index cards numbered from 1 to 25 (or even random >four digit numbers if you are teaching radix sort) eliminates >distractions. > I managed to do the "fun" experiment once. Take three students >and have them learn Quicksort, Heapsort, and Bubblesort on "small" >decks. At even 50 to 60 cards, the students doing Heapsort and >Quicksort are racing each other*, and the Bubblesort victim is still >hard at work well after they have finished. > *The race really is to finish the Quicksort before the Heapsorter >has built a heap. This also shows why quicksort is quick, since the >Quicksort step of picking up the cards is O(n), not O(n log n) Of course, if any are using radix sort, they're done well before anyone else. Why this O(n) method of sorting isn't taught more widely escapes me. Steve Heller, author and software engineer http://ourworld.compuserve.com/homepages/steve_heller