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</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=EN-AU link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Hi Mike,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Sorry about the wording when I suggested the initial stack was in a full state. What I meant was it was not possible to infer that the initial stack represents the “capacity” of the stack data structure. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Perhaps the question could have been worded:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> Consider the following stack displaying the maximum capacity of the stack data structure. And a stack drawn with 5 totally different values <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Further help would have been to state the initial top of stack pointer was set to 1 rather than have a box labelled TOP with a separate stack drawn with only 2 elements in it. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Actually, apart from stimulating discussion about stack implementations, as an interesting aside, doesn’t it bring into sharp focus the difficulties in the different numbering of data structure elements in the traditional C like languages from 0 to the more modern VB family which use 1 as the starting element ?? <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Sure the pointer is the key to the TOS value but again in every encounter with stacks in my university days I never saw stacks with popped elements that did not display the stack with the element removed. It only adds to the confusion to show a stack with all elements in place but only with the TOS value to guide you to the actual Top of Stack position. A detail perhaps, but more confusion.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Your insight has been very useful Mike but it is clearly from the point of view of an examiner. I guess Mark and I have been trying to make sense of it as a student who may not have the capacity to infer what makes a trivial and what makes a non trivial component in the question. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>How many people would expect a Stack Full outcome as inevitable in some part of the answer , just because it was mentioned in the question ?? Should students connect these clues and try to make the answer fit the question without any evidence that these assumptions are valid ? <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>A very useful discussion Mike. Thanks for your input and insight.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Kind Regards<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Kevork Krozian<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Edulists Creator Administrator<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>www.edulists.com.au<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>tel: 0419 356 034<o:p></o:p></span></p></div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'> sofdev-bounces@edulists.com.au [mailto:sofdev-bounces@edulists.com.au] <b>On Behalf Of </b>Mike Brookes<br><b>Sent:</b> Sunday, 1 May 2011 4:56 PM<br><b>To:</b> Year 12 Software Development Teachers' Mailing List<br><b>Subject:</b> Re: [Year 12 SofDev] Sample Exam Questions<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal style='margin-bottom:12.0pt'>G'Day again<br><br>Whilst 'tis true that this question on the end of year exam would unduly stress the little dears, to play devil's advocate, it does have a useful function as a sample to provoke discussion about what assumptions must be made. i.e. for the question to have a non trivial answer, what assumptions are necessary? <br><br>Firstly the memory locations used for the stack do not have to be initialised to 0 or any other value when the stack is created. The pointer is the only thing that must be initialised.<br><br>If you assume the stack starts at 1 instead of 0, then the stack will not be full after step 6 reducing the value of the question.<br><br>I also assumed that the bottom two values were in bold for a purpose, the most obvious (at least to me) being that they were valid existing members of the stack. <br>At the start of the question the stack is not full, the TOS pointer is 1, the stack would be full when it reaches 4, so the non-bold values were from previous uses of the stack. NB. a pop does not delete the value from the stack, it just changes the TOS pointer.<br><br>It may well be that a different set of assumptions will produce a meaningful answer, these were the first consistent set I thought of.<br><br>If you assume an empty stack at the start then, given that the pointer is 1 at the start of the question, the TOS pointer must point to the next available location (closer to convention) and the numbering must start at 1 instead of 0. In this case the stack is not full after step 6 so another push step would be needed in the question.<o:p></o:p></p><table class=MsoNormalTable border=0 cellspacing=0 cellpadding=0 width=817 style='width:612.75pt'><tr><td style='padding:0cm 0cm 0cm 0cm'></td><td style='border:none;padding:0cm 0cm 0cm 0cm' width=784 colspan=13><p class='MsoNormal'> </td></tr><tr style='height:15.75pt;min-height: 15.75pt'><td width=35 style='width:26.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt;min-height: 15.75pt'></td><td width=91 style='width:68.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=31 style='width:23.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=124 style='width:93.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=29 style='width:22.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=31 style='width:23.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=31 style='width:23.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=64 style='width:48.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=64 style='width:48.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=64 style='width:48.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=64 style='width:48.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=64 style='width:48.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=64 style='width:48.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=64 style='width:48.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td></tr><tr style='height:15.75pt;min-height: 15.75pt'><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt;min-height:
15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td colspan=7 style='border:none;border-right:solid windowtext 1.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt;border-color:-moz-use-text-color black -moz-use-text-color -moz-use-text-color'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Stack at start and after each step<o:p></o:p></p></td></tr><tr style='height:15.75pt;min-height: 15.75pt'><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt;min-height:
15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Step<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Function<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Top<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Output<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Start<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Step 1<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Step 2<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Step 3<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Step 4<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Step 5<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Step 6<o:p></o:p></p></td></tr><tr style='height:15.0pt;min-height: 15pt'><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt;min-height: 15pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>1<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Push (23)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>2<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Item added (23)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'></td><td rowspan=5 style='border:none;border-bottom:solid windowtext 1.0pt;padding:0cm 0cm 0cm 0cm;height:15.0pt;border-color:-moz-use-text-color -moz-use-text-color black'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Stack position<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>5<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>92<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>92<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>92<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>92<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>92<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>92<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>92<o:p></o:p></p></td></tr><tr style='height:15.0pt;min-height: 15pt'><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt;min-height: 15pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>2<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Push (18)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> 3<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Item added (18)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>4<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>75<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>75<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>18<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>18<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>75<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>75<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>47<o:p></o:p></p></td></tr><tr style='height:15.0pt;min-height: 15pt'><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt;min-height: 15pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>3<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Pop<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>2<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Item removed (18)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>3<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>23<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>23<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>23<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>23<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>23<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>92<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>92<o:p></o:p></p></td></tr><tr style='height:15.0pt;min-height: 15pt'><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt;min-height: 15pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>4<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Push (75)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> 3<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Item added (75)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>2<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>83<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>83<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>18<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>18<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>75<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>75<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>75<o:p></o:p></p></td></tr><tr style='height:15.75pt;min-height: 15.75pt'><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt;min-height:
15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>5<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Push (92)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>4<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Item added (92)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>1<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>52<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>23<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>23<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>23<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>23<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>23<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>23<o:p></o:p></p></td></tr><tr style='height:15.75pt;min-height: 15.75pt'><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt;min-height:
15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>6<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Push (47)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>5 <o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Item added (47)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td></tr><tr style='height:15.75pt;min-height: 15.75pt'><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt;min-height:
15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Top<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>1<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>2<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>3<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>2<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>3<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>4<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>5<o:p></o:p></p></td></tr></table><p class=MsoNormal><br>One would hope that a "real" question would at least have numbered the stack positions and provided a key to explain what the bold signified. A question to sort sheep from goats????????????<br><br>Mike<o:p></o:p></p><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'>1<o:p></o:p></p><p class=MsoNormal>On 1/05/2011 12:12 AM, Kevork Krozian wrote: <o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>Hi Mark and Mike,</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> I am a little late on the scene but have to support Mark here.</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>The question on stacks is more a puzzle than a reasonable problem for a student to solve in limited time.</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>The question begins with a picture of a stack to consider....... which suggests the starting position of the problem. Apparently it is in a full state .... and that can be determined from ?????</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>Then, a push (23) is introduced. Hang on, I thought we had a stack to consider with 5 elements. Are we adding another 23 or picking up half way through the introduced stack ? </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>Where is it suggested that the introduced stack is in a “stack full” state ? </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>The push and pop operations are not the problem, just the starting position of the problem. When is the beginning is what got me first. The bold items were no help as I didn’t consider them to be significant.</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>Also, the item Top (1) might mean top of stack to the writer, but only adds to the confusion as it is not obvious it means the top of the stack when we start with a stack with 5 elements. </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>I have gone through my 2<sup>nd</sup> year Data Structures textbooks and have a strong recollection of the 1982 exams I did ( why wouldn’t I ?? ) on stacks and data structures and there was always a pointer or arrow (with a value in a variable ) showing the top of a stack at the beginning of a question and the requirement was to draw the stack through the various states after push and pop functions. Apart from that we either have empty or full states. </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>I can’t see how this question would have helped in any way to show student’s understanding of a stack and its functions.</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>Kind Regards</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>Kevork Krozian</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>Edulists Creator Administrator</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><a href="http://www.edulists.com.au">www.edulists.com.au</a></span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>tel: 0419 356 034</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> </span><o:p></o:p></p><div style='border:none;border-top:solid windowtext 1.0pt;padding:3.0pt 0cm 0cm 0cm;border-color:rgb(181, 196, 223) -moz-use-text-color -moz-use-text-color'><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> <a href="mailto:sofdev-bounces@edulists.com.au">sofdev-bounces@edulists.com.au</a> [<a href="mailto:sofdev-bounces@edulists.com.au">mailto:sofdev-bounces@edulists.com.au</a>] <b>On Behalf Of </b>Mark KELLY<br><b>Sent:</b> Wednesday, 27 April 2011 2:36 PM<br><b>To:</b> Year 12 Software Development Teachers' Mailing List<br><b>Subject:</b> Re: [Year 12 SofDev] Sample Exam Questions</span><o:p></o:p></p></div><p class=MsoNormal> <o:p></o:p></p><p class=MsoNormal style='margin-bottom:12.0pt'>Thanks for the bone, Mike. Woof! It finally let me work out the many assumptions underlying the question: and after all that, I'm not wagging my tail.<br><br>I think the question is far from clear, and I doubt students would make much of it in a real exam.<br> <br>- It does not, for example, say that the stack is zero-based. If one assumes (as I did) that the stack indexing starts at 1, the whole thing changes and nothing makes sense.<br>- It does not indicate what the mysterious bolding of the bottom 2 items is meant to represent. If the examiners invent their own conventions, they should explain them to us.<br>- It does not tell us that the stack pointer in updated <b>before</b> a push/pop instead of being changed afterwards, as often happens. Again, this changes everything.<br>- One has to realise that the stack is expanding from the bottom and not from the top. Stacks are often represented growing in either direction.<br><br>When it comes to real-world stack implementation, there are so many different options such as these that I found the question mind-boggling while I went through the permutations of possible readings.<br><br>Grrr.<o:p></o:p></p><div><p class=MsoNormal>On 21 April 2011 14:45, Mike Brookes <<a href="mailto:mikebr@tpg.com.au">mikebr@tpg.com.au</a>> wrote:<o:p></o:p></p><div><p class=MsoNormal>Hi Mark et Al<br><br>For the question to make sense one has to make the assumption that the stack positions start at the bottom with position zero and go up to position 4 which is the top of the stack. At the start the bottom two (in bold on the PDF) are valid, hence the top of stack pointer showing 1. <br><br>Below is the completed table and the stack at the start and after each step:<o:p></o:p></p><table class=MsoNormalTable border=0 cellspacing=0 cellpadding=0 width=817 style='width:612.75pt'><tr style='height:15.75pt;min-height: 15.75pt'><td width=35 style='width:26.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt;min-height: 15.75pt'></td><td width=91 style='width:68.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=31 style='width:23.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=124 style='width:93.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=29 style='width:22.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=31 style='width:23.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=31 style='width:23.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=64 style='width:48.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=64 style='width:48.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=64 style='width:48.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=64 style='width:48.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=64 style='width:48.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=64 style='width:48.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td width=64 style='width:48.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt'></td></tr><tr style='height:15.75pt;min-height: 15.75pt'><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt;min-height:
15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td colspan=7 style='border:none;border-right:solid windowtext 1.0pt;padding:0cm 0cm 0cm 0cm;height:15.75pt;border-color:-moz-use-text-color black -moz-use-text-color -moz-use-text-color'><p class=MsoNormal>Stack at start and after each step<o:p></o:p></p></td></tr><tr style='height:15.75pt;min-height: 15.75pt'><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt;min-height:
15.75pt'><p class=MsoNormal>Step<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal>Function<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal>Top<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal>Output<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal>Start<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal>Step 1<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal>Step 2<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal>Step 3<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal>Step 4<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal>Step 5<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal>Step 6<o:p></o:p></p></td></tr><tr style='height:15.0pt;min-height: 15pt'><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt;min-height:
15pt'><p class=MsoNormal>1<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal>Push (23)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal>2<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal>Item added (23)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'></td><td rowspan=5 style='border:none;border-bottom:solid windowtext 1.0pt;padding:0cm 0cm 0cm 0cm;height:15.0pt;border-color:-moz-use-text-color -moz-use-text-color black'><p class=MsoNormal>Stack position<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>4<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>92<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>92<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>92<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>92<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>92<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>92<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>92<o:p></o:p></p></td></tr><tr style='height:15.0pt;min-height: 15pt'><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt;min-height:
15pt'><p class=MsoNormal>2<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal>Push (18)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal> <o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal>Item added (18)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>3<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>75<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>75<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>18<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>18<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>75<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>75<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>75<o:p></o:p></p></td></tr><tr style='height:15.0pt;min-height: 15pt'><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt;min-height:
15pt'><p class=MsoNormal>3<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal>Pop<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal>2<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal>Item removed (18)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>2<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>23<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>23<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>23<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>23<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>23<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>23<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>23<o:p></o:p></p></td></tr><tr style='height:15.0pt;min-height: 15pt'><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt;min-height:
15pt'><p class=MsoNormal>4<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal>Push (75)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal> <o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal>Item added (75)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>1<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>83<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>83<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>83<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>83<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>83<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>83<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.0pt'><p class=MsoNormal align=right style='text-align:right'>83<o:p></o:p></p></td></tr><tr style='height:15.75pt;min-height: 15.75pt'><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt;min-height:
15.75pt'><p class=MsoNormal>5<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal>Push (92)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal>4<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal>Item added (92)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='text-align:right'>0<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='text-align:right'>52<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='text-align:right'>52<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='text-align:right'>52<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='text-align:right'>52<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='text-align:right'>52<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='text-align:right'>52<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='text-align:right'>52<o:p></o:p></p></td></tr><tr style='height:15.75pt;min-height: 15.75pt'><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt;min-height:
15.75pt'><p class=MsoNormal>6<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal>Push (47)<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal> <o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal>Stack full<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td></tr><tr style='height:15.75pt;min-height: 15.75pt'><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt;min-height:
15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal>Top<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='text-align:right'>1<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='text-align:right'>2<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='text-align:right'>3<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='text-align:right'>2<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='text-align:right'>3<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='text-align:right'>4<o:p></o:p></p></td><td style='padding:0cm 0cm 0cm 0cm;height:15.75pt'><p class=MsoNormal align=right style='text-align:right'>4<o:p></o:p></p></td></tr></table><p class=MsoNormal><br><span style='color:#888888'>Mike Brookes <br>Semi retired gentleman from Copperfield College</span><o:p></o:p></p><div><p class=MsoNormal><br><br>On 21/04/2011 1:35 PM, Mark KELLY wrote: <o:p></o:p></p><p class=MsoNormal>Would someone be kind enough to throw me a bone about the stack question - Q3?<br><br>I thought I knew stack implementation from my assembly language days with Z80... this question feels like walking into someone's half-finished thought process. I'm really confused about this.After half an hour of conjecture, I’ve tried four times to ask a series of sensible questions to make sense of it, and have failed every time. <o:p></o:p></p><p class=MsoNormal> <o:p></o:p></p><p class=MsoNormal>The only apparent answer involves time travel, reversed arrays, irrelevant stack pointers and bogus bolding of stack items. The relationship between the stack and the table is only the beginning of the problem...<o:p></o:p></p><p class=MsoNormal> <o:p></o:p></p><p class=MsoNormal>I’d be delighted if anyone could walk me through this...<o:p></o:p></p><p class=MsoNormal> <o:p></o:p></p><p class=MsoNormal>Regards<o:p></o:p></p><p class=MsoNormal>Mark<o:p></o:p></p><p class=MsoNormal> <o:p></o:p></p><p class=MsoNormal> <o:p></o:p></p></div></div><p class=MsoNormal><br>_______________________________________________<br><a href="http://www.edulists.com.au" target="_blank">http://www.edulists.com.au</a> - FAQ, Subscribe, Unsubscribe<br>IT Software Development Mailing List kindly supported by<br><a href="http://www.vcaa.vic.edu.au" target="_blank">http://www.vcaa.vic.edu.au</a> - Victorian Curriculum and Assessment Authority and<br><a href="http://www.vcaa.vic.edu.au/vce/studies/infotech/softwaredevel3-4.html" target="_blank">http://www.vcaa.vic.edu.au/vce/studies/infotech/softwaredevel3-4.html</a><br><a href="http://www.vitta.org.au" target="_blank">http://www.vitta.org.au</a> - VITTA Victorian Information Technology Teachers Association Inc<o:p></o:p></p></div><p class=MsoNormal style='margin-bottom:12.0pt'><br><br clear=all><br>-- <br>Mark Kelly<br>Manager of ICT, Reporting, IT Learning Area<br>McKinnon Secondary College<br>McKinnon Rd McKinnon 3204, Victoria, Australia<br>Direct line / Voicemail: +613 8520 9085, Fax +613 9578 9253<br><a href="mailto:kel@mckinnonsc.vic.edu.au" target="_blank">kel@mckinnonsc.vic.edu.au</a><br>VCE IT Lecture Notes: <a href="http://vceit.com" target="_blank">http://vceit.com</a><br>Moderator: IT Applications Edulist<br><br>All generalisations are false, except this one.<o:p></o:p></p><pre><o:p> </o:p></pre><pre><o:p> </o:p></pre><pre>_______________________________________________<o:p></o:p></pre><pre><a href="http://www.edulists.com.au">http://www.edulists.com.au</a> - FAQ, Subscribe, Unsubscribe<o:p></o:p></pre><pre>IT Software Development Mailing List kindly supported by<o:p></o:p></pre><pre><a href="http://www.vcaa.vic.edu.au">http://www.vcaa.vic.edu.au</a> - Victorian Curriculum and Assessment Authority and<o:p></o:p></pre><pre><a href="http://www.vcaa.vic.edu.au/vce/studies/infotech/softwaredevel3-4.html">http://www.vcaa.vic.edu.au/vce/studies/infotech/softwaredevel3-4.html</a> <o:p></o:p></pre><pre><a href="http://www.vitta.org.au">http://www.vitta.org.au</a> - VITTA Victorian Information Technology Teachers Association Inc<o:p></o:p></pre><p class=MsoNormal><o:p> </o:p></p></div></body></html>