“ VAs in Computer Science THE (NEW) TURING OMNIBUS THE (NEW) TURING OMNIBUS 66 Excursions in Computer Science A. K. Dewdney ‘The University of Western Ontario ieacy of Congress Catnoping-Puiaion Date "Ws non) Pudge AX. Dewey ede ne. ie'brigr aie 5 girepin Is copa 8 ae Henne nd cope, op © 969 XNepst ofthat nye peices ty sn mesh Bionic soy Ce 28) glad Sevon! pti 1996, KRD edtcated tothe memory of (1902-1969) German tess, tenes oat and jm, the human cabbla CONTENTS Prec o feos wl ABIRTHIB Cooking tp Programs — 1 ANTE AUTNATA 72 Aiack Bax 8 HISTEME OF UNSC scion Races 18 IMILATIN 72 Monte Carts Mewod — 1 BOOS THEE caver one tegic A BANE TEES The Movax tested 3 THE EMNSEY HEMRERY xu Computers MD AMOR RINGERS Toe chastin Kotmogoreey Theory — MD WATHEMATERL RESEARCH Toe Meeltires Sor SE wi THE (ube) TURIRE ONOIBUE 1e " @ B “ 6 6 a i a ROSIN COBRETNERS carmate Debuguing EME THES Traversal ano Naiwemance RISIRECTNG CWE Pcscre from Space DBMLEA UE Expressions ane crews AD TERIAL UNOS rrmping Woras TRE MD SPICE AMPEKTY re sg-0 Noeston We GEAEMG AEDITINS Sofutions Thar BvoWve THE RAMON ACERS MACHINE ay Abstract PUNE GIBVEE Sono0s) srrerpoiasion 8 DONPOTR WBN Hotydcdvat Scenes 1H HAMM WHS cut TE NENTON-RAPREIN METH. inci Rare IMR SPAEKEIE TREES Fs Angorivmn MEAT SIMMS Lentenmayer Syerems REMERON be Steins Curve — 1H HST MIUTPLEATION Divzae and Conquer AOOMETRRIG sursn ae Tar cases torre FEMERRINE cack orvivon MH Minimization — 18 nputer 1 w sty we 10 ™ BIGIRS AM MLTPLBERE svanpetaring Memory WAT SOUIMNE ross-Secrional X-Rays THE PATTON PROMEM 4 eseuco,fecrAigorteine 20 THN WACHMIES The SimpteseCompssers 07 THE FAST FOUMER TRAKENAM etssrbucing rages FANLOE CMPETATIUN Spano! Computers — 128 SATBAMBUTY 4 Conaved Problems — BH ASWENTAL SETHE A tower Bowne! on speed — 28 EDL WETWORIS THAT LEN Conorineg Coortinatas FUG KEY CRYFOERARY ect Secrots 0 EUENTIAL EREUTS 4 computor Stomory 2 mn m ONENPUTLE FARETIME 76 Busy Aeaver robles — BE HEAPL MND WERBEE re kaststSortop Sorts 0 NPCOMPLEENESE oe wet of mrsceabusiy OD MBER SYSTEME FOR COMPUTE ciieseAvibmcrtc ORE STORE AY IMMUIKE oe Key ithe adress — ELILUR AUTOMATA re cme opis 298 HOES THEDREN ues an ote MY SELFRPLOATINE CWMPTTENS cta'stacbine STONE WHEE a cas ma Ona ree THE SEAN A simpitied Computer M0 SHANI WHER re ztvcve Codes 3M DETECTING PRIMES An Atportioe sa: aimost twas Works UOVERRAL THANG ACHES Conppers us Frogrems 908 TET SORES ctfinan Conting 8 UGK WPEMTIG STETENS nocisiragping ibe Comper Hel NPSGHPLTE PRBLOMS be Tree gitniraciabitiy WT EATON AA REIRSON Toe Towrs op Francs 3 UB) COMPUTERS circuits Ssicon MR WEAR PMELANUINE ine Srapiex Mozbod TR MEUCATE CHLEMUIS 70 Resotutow Mextod — BE THE HLTH PREBLE 20 ncrmputante SEL COUPOTER VRBEES 4 Sctuvare ovasion 8 SEMAINE STINBE The Boyer-oore atgarttims — MOE PMRAUEL GONPLTING Processors with Conmecions — MB THE WORD PROBLEM Diceraries as Programs — ANE 086 FIGRMIMINE Zrotngue wo Espertie MD RENTON, IT IEEE Py r-reaevesf Queries AD CHURCH THIS 4st comeusorsare Created Kua — HA Int a8 te PREFACE ‘he (¥eu) Turing Omnibusisa veticl of learning that viss the major le nalsof somputer science. The ur siepsat monuments thew. vsls maior {Gehniques, and travels the avenes of a9p tation. Ths new euition of 7 Siuning Conthusteatares anew ion, note, with nes nlaurks added tbs {inary nthe Prefice ollie 1989 edition, | desesibed ene collestionas "nota exharscine survey «but Kugely subjecrve.” Wich six new chapters an Than chaprers revised the subjoctity martes less. And uke book is that mie ‘loser heing extinustive, a least sts narra! level of expasition “The metaphor of a fouring ominous emerged during a sabbalicl tcken oxfordia 1980. 1981, large, fed double-cecker cmnibuses roared tiem stop stop inthe urban Oxford landscape and, -antter south, in London. Hese wasa pmol cf Engl, he land oF Alan Turing, hose ripe muathesratiea imaging ‘ion was fueled by Janasies of mechanized ineLect. Tusing’s greatest single lege, the Turing machine ise, became the Desvsnoxen vehicle for che cemnecging theory of eo mputablity. Wonerluly simple, wth only ts moe, parts it can be explain! to tee manos woman in the see. Yer embeaces te everythingulst we ate by the word “computable”! Nor surpeisingly, this bool, ‘isiis2 Turing machine, sul in working order ‘Thos Tring Onndbusbvegan dns Lael sbbical at Oxfoed. My host wis Doniaie Welsh, a well known mathertician of Merton College Inter ested inal things compe taonal, Welsh would couduct occasional wales along the Chere. One day he bemecned he lack oF wood, comprehensive Intra duction ra coment na, noca dry ext thete ae plenty 0! tkoxe—ut semi Popularcomnendinm of computer science, the "good bits. "as ae salle them, "The topics" besa, "must have charm ora eat, velevance "Lele imme late sympathy with the idea. Tron had offen wished for something stale, albeit more academically directed. Over succeeding manihs we put down list ‘of topics on paper. Welsh, not being on sahhatical atthe Time, give wp the project bu encouraged me to continue. ‘Sometime during my childlisod Tenceuntezel he tedtonal image a id that erodes mountain by taking ssingls stone from ie cee-y yearn Ure, a mwunita any dseppearby ths method —andappear elects. That ws Hy Feely sbout the bicessental ros of Tbe Turing Omnibus Hom 1981 19 1938 wher: I completed tie est usaf, ntonished ocr move at Fe power of incremental work. The epics cue not only om dhe original ist deasenip with ‘Welsh, but also tom bagering colleagues st my home instiston, the Univer sity of Western Gntaro, ane other colleagues meat conferences ail vee Noh Americaduvig the ear 1980s Since the publicaiomof ae 1989 eit, have badgered even more people ard, asa result, developed aucre topics. Two ideas, the Mandetheotsecand compute viuses,eginatediu my Compater Recrea tions column in Scienae American magnaine The result, Tho (Neu) Tureng Omsulbus, is acwually mote thin ¢ “x” and comes, by vine ofiterew material, closer ta belng at “omiibs” in the ves fl coarplete collection. This honk is designed co appeal oh 0 tie educates layperscn endo the studen: of computer sence. x hw sshal possible? The ‘ulwer lies i the variety oftreatraents aswell ax topics Some ofthe topics a ihersauly exsy ue I ave been lucky enough to stumle upon just the ig expostory mechansms. someor the wppesare inkeremipleep ¥ comp ica ‘ax there 9 way amunda certain rigor, inehiding occasional aerate symbolim. Forstudents of emputer science, che 66 chapters thatfollow weil ve: sneak review ol the major ideas and techaiques they wall encounter ia ‘Rew inde igeadate cazeero nd some they mas only eneounect as grachnte sticents, kor professes of vompuler seat muy colleagues, the 66 chaps WillamaunicOa Seah veovew. Tring w emeraber just howth= Hoyce-Moors sing: watching, slgoridan wene le gc caere tm Chapter 61, Searching Strings. Ae fer yout lectures ifyou lke to deliver your cwa material cis hank may 9¢ What FOU've Deen lookiaglor a: ove ens of is spectrum of ses, re (New Tartag Ons