AfterwritingGATEpaper,IwassureofnotexpectinganythingfromtheGATEthentheweirderanswerkeysofdifferentinstitutesaddedtheconfusionandpressure.So,Idecidedtofocusonmyjobandwasbusywiththeboringtestingworkinoffice.11thMarchsomebodypostedlinkofGATEresultIcheckedmineitwasAIR320,a400KWshockIwasstunnedformovementIcheckedwithfewforvalidityoftheresultthenrestof4daysgoesprayingtomakeitreal.

Thencometheday15thMarch,andyesitwassameAIR320IwasincloudnineandsureofgettingatleastIITH/IITG.But,withinfewdaysIfoundmyselfinthecloudofsorrowsanddisgustaspeoplefromlastyearwithhigherrankwerehavingmorescorethanme.Butthen,myseniorsandfriendssuggestedmetofocusonwritten/interviewsoIdid.

FirstconfrontwasIITM(M.S),Icrackedthewrittenanddeliveredwellininterviewbutwasnotshortlisted.

SecondbattlewasofIITK:waitingticketandnighmaretotravelfromMumbaitoKanpur.Iwritewellinwrittenandwasamongthetop.SeniorsthereweresayingthatIamhavingverygoodchancesnow.Thencomethemovement.Ienteredinroom:1.Howwillyoufindshortestpathinweightedgraph?Dijkstrasalgorithm.2.Whatiscomplexity?Iactedstreetsmarthere,wastryingtospendmoretimeonquestionasIwascomfortable.IsaiduiniterativeapproachwewouldneedO(n^2)forfindingshortestpathbetweenallpairs.3.Isthereanyotherapproach?ActedlikerecallingandthensaidSirIguesstheuseofpriorityqueqeswouldmakeitfaster,wecanachieveitinO(nlogn).Satisfied4.Whatisdifferencebetweenheapandpriorityqueqe?Wecanuseheapaspriorityqueqe.BurHeapshouldthenprovidethefunctionforinsertion,reportmin,extractMin.Satisfied.5.ForreportMinandinsertwhichdatastructureshouldbeused?andwhatwouldbecomplexity?(thiswasaquestionfromwrittentest).Ianswerditwrongintest.IsaidMinheapandcomplexityforinsertionO(logn)&forreportMin:O(logn).But,againIwaswrong.TheytriedtogivemehintbutIwasnotabletogetit.CorrectanswerwaswecanuseanarrayandaminvariableandeverytimeweinsertelementjustcheckitwithcurrentminandupdatetheminvaraccordinglyThiswasexplainedtomebySwapnilafterinterview.

6.IsitabletohaveinsertioninO(1)?YeswecoulduseFibonacciheap.

7.IfwehaveanDSinwhichinsertionanddeleteMinisO(1)thenwhatwoulditsuse?WecouldusetheinsertionofnelementinO(n)inthatDSandthenwecouldapplydeleteMin()ntimetogetsortedarraysowecanhavethesortinginO(n).

8.Aretheresortingalgorithmsortinginntime?IfyouareaskingaboutasymptoticallyO(n)therearethealgorithslikebucketsortandradixsort.Butifyouaskingaboutexactlynoperationthethereisnone.

9.How?Because,theprimeoperationforsortingiscomparisonandweneedatleastO(nlogn)comparison.

10.Proveit.Iwasabouttostanduptoexplainonboard,whiledoingsoIsaidwecanproveitbyusingthedecisiontree.Theystoppedmeandaskednextquestion.

11.Areyoucomfortablewithanyothersubject?Yes,TOC.

12.IwillaskyouonlysinglequestionIssetofwellformnoisregular?(Wellformnomeans1,000propernowrittenwith,).Thiswasnighmareforme.Iwasblank.Theysaidmethatyoucanuseblackboard.Itriedbutwasnotgettingnehow.ThenIsaidsomeweiredthingthatitsnotregularwecanproveitbypumpinglemma.ThentheyexplainedmethatIamunabletouselemmaproperlyandthisisregular.Iwasdisappointed.

Wecanproveitbyformingregularexpressionforitas:

(19)^?.((09.09),*(09.09.09)?)

Iwasnotawareof?whichmeans0/1instance.

Iwasinnotsureaboutclearinginterviewbutgoodmarksinwrittenwereincreasingmyconfidence.

IITB(RA)

Nowmyeticketgetcancelwithlaststatusaswaiting4.ThankfullytherewassmespecialtrainboardedingeneralboggyanditwasemptycamesleepinginittoMumbai.On20thmorningtherewaswrittenofRA.Abittoughandsubjective,AftertestwewentforLunchinmidwaysomebodysaidIITKresultsareout.IcheckedIwasin.ThenIattendedtheRAinterviewinWebapplicationproject.1.Atablecontainsyearandcoursesinthatyearalongwithotherdetails.WritequerytoprintyearfromwhichcourseCS206wasoffered..

Selectmin(year)fromTable

wherecourse=CS206.2.Howcanyouuseminfunctionwithoutusinggroupby?Iwasexpectingthisquestion.Isaid,Ifyoudonotapplythegroupbyclauseitwillmakeasinglegroupofallrowswhicharefilteredoutafterwhereclause.

3.TheaskaboutmyJobexperience.Answered.

4.AskaboutS/Wscalability.Isitgoodtohavesingleserverwithmanyprocessorsortohavedifferentservers?

Itstreadoff.Ifyouhavesingleserverwithmanyprocessoritwouldbefasterbutthenavaibilitywouldbelow.Andifyouhavemultipleserversthenavaibilitywouldbemore.Buttheninternalcommunicationandroutingtherequesttoparticularserverwouldbeoverhead.Soweprefermultipleserverincaseofhightraffic.

5.FewmorequestionaboutJSPandall.Ianswered

IwasselectedinIITB(RA)

BARC.

Iwaschillandwasoutoftension,

1.Explainyourproject.

Didwell.2.AskedmetowritesomequerybasedonDBofmyproject.Didit.3.WhatisWebservices?Howitworks.Webservicesareusedtolettwodifferentapplicationtocommunicateirrespectiveofthereplatforms.XML/SOAPareusedforthesame..4.WhatareACIDproperty?Explainedwiththeexamples.5.Listyourfavsubjects.OS,DB,TOC,Descrete,DS6.Withwhichlanguagesyourcomfortable?C,C++,Java

7.Writeprogramtochecknoof1sinbinaryrepresentationofintegerwhichuseri/pWithfewhintsfromtheresideIwasabletowriteitthewaytheywanted.main()

{inta,count=0,t=1couta;

For(inti=0;i

*(base+size)=temp;

Reverse(base+1,size1)

}

}

9.Whatisprincipleofoptimality

thereare2optimalityprinciples:1.Temporal:datawhichisreferredislikelytobereferredagaininnearfuture,soitsgoodtokeepitincache.

2.Spatial:Addresslocationneartheaddresseslocationbeingaccessedarelikelytobeaccessedinnearfuturesoitsgoodtokeepblockofdataratherthansingledataelement.

10.Howpagesharinghappens?Therearedifferentcontrolbitsinpagetableentrieslikehardlockwhichmeansrespectivepageisneverswappedoutusedforkernelpages.Similarlythereferencecountismaintainedforthepagesindicatingthenoofprocessescurrentlyreferencingthepage.Sothiscountisusedinpagereplacementalgoandpageswithmorecountarenotswapped.

11.Whatareothercontrolfieldinpagetable.1.Valid/invalid:Thisindicatewhetherthepagetableentryisvalidorinvalid.Ifpagewithvalid/invalidbitsetisreferredthenpagefaultoccure.2.Dirtybit:Ifpageismodifiedthendirtybitissetindicatingthatpageneedstobewrittenback.

12.Explaintheprocessofpagefault.Whenapagewithvalid/invalidbitsetisaccessedOStrapisgenerated.Itcheckswhetheritssegmentationfaultoritsgenericpagefault.Ifitssegmentationfault,processisswappedout.IfitsgenericpagefaultthenOSwillcheckforemptypageinmainmemoryandloadtheframeintothepageandthenupdatethepagetableandrestarttheinstruction.

FewmorequestionsonOSconceptsandactivationrecordsanditwasover.

Iwasaskedtowaitandin5minute1ofpanelmembertakemeinsidewheretheygivemethewhiteslip.