Search Results

Search found 25563 results on 1023 pages for 'negative number'.

Page 218/1023 | < Previous Page | 214 215 216 217 218 219 220 221 222 223 224 225  | Next Page >

  • C# Taking a element off each time (stack)

    - by Sef
    Greetings, Have a question considering a program that stimulates a stack.(not using any build in stack features or any such) stack2= 1 2 3 4 5 //single dimension array of 5 elements By calling up a method "pop" the stack should look like the following: Basically taking a element off each time the stack is being "called" up again. stack2= 1 2 3 4 0 stack2= 1 2 3 0 0 stack2= 1 2 0 0 0 stack2= 1 0 0 0 0 stack2= 0 0 0 0 0 - for (int i = 1; i <= 6; i++) { number= TryPop(s2); //use number ShowStack(s2, "s2"); } Basically I already have code that fills my array with values (trough a push method). The pop method should basically take the last value and place it on 0. Then calls up the next stack and place the following on 0 (like shown above in stack2). The current pop method that keeps track of the top index (0 elements = 0 top, 1 element = 1 top etc..). Already includes a underflow warning if this goes on 0 or below (which is correct). public int Pop() { if(top <= 0) { throw new Exception("Stack underflow..."); } else { for (int j = tabel.Length - 1; j >= 0; j--) { //...Really not sure what to do here. } } return number; }/*Pop*/ Since in the other class I already have a loop (for loop shown above) that simulates 6 times the s2 stack. (first stack: 1 2 3 4 0, second stack 1 2 3 0 0 and so on.) How exactly do I take a element off each time? Either I have the entire display on 0 or the 0 in the wrong places / out of index errors. Thanks in advance!

    Read the article

  • DjangoUnicodeDecodeError while storing pickle'd data.

    - by Jack M.
    I've got a simple dict object I'm trying to store in the database after it has been run through pickle. It seems that Django doesn't like trying to encode this error. I've checked with MySQL, and the query isn't even getting there before it is throwing the error, so I don't believe that is the problem. The dict I'm storing looks like this: { 'ordered': [ { 'value': u'First\xd1ame Last\xd1ame', 'label': u'Full Name' }, { 'value': u'123-456-7890', 'label': u'Phone Number' }, { 'value': u'[email protected]', 'label': u'Email Address' } ], 'cleaned_data': { u'Phone Number': u'123-456-7890', u'Full Name': u'First\xd1ame Last\xd1ame', u'Email Address': u'[email protected]' }, 'post_data': <QueryDict: { u'Phone Number': [u'1234567890'], u'Full Name_1': [u'Last\xd1ame'], u'Full Name_0': [u'First\xd1ame'], u'Email Address': [u'[email protected]'] }>, 'user': <User: itis> } The error that gets thrown is: 'utf8' codec can't decode bytes in position 52-53: invalid data. Position 52-53 is the first instance of \xd1 (Ñ) in the pickled data. So far, I've dug around StackOverflow and found a few questions where the database encoding for the objects was wrong. This doesn't help me because there is no MySQL query yet. This is happening before the database. Google also didn't help much when searching for unicode errors on pickled data. It is probably worth mentioning that if I don't use the Ñ, this code works fine.

    Read the article

  • review of a codility test - pair_sum_even_count

    - by geoaxis
    I recently took an online test on codility as part of a recruitment process. I was given two simple problems to solve in 1 hour. For those who don't know codility, its an online coding test site where you can solve ACM style problems in many different languages. if you have 30 or so mins then check this http://codility.com/demo/run/ My weapon of choice is usually Java. So on of the problems I have is as follows (I will try to remember, should have taken a screenshot) Lets say you have array A[0]=1 A[1]=-1 ....A[n]=x Then what would be the smartest way to find out the number of times when A[i]+A[j] is even where i < j So if we have {1,2,3,4,5} we have 1+3 1+5 2+4 3+5 = 4 pairs which are even The code I wrote was some thing along the lines int sum=0; for(int i=0;i<A.length-1;i++){ for (int j=i+1;j<A.length;j++){ if( ((A[i]+A[j])%2) == 0 && i<j) { sum++; } } } There was one more restriction that if the number of pairs is greater than 1e9 then it should retrun -1, but lets forget it. Can you suggest a better solution for this. The number of elements won't exceed 1e9 in normal cases. I think I got 27 points deducted for the above code (ie it's not perfect). Codility gives out a detailed assessment of what went wrong, I don't have that right now.

    Read the article

  • Word 2007 COM - Can't directly access a page when word is set to invisible

    - by Robbie
    I'm using Word 2007 via COM from PHP 5.2 Apache 2.0 on a windows machine. The goal is to programmatically render jpeg thumbnails from each page in a Word document. The following code works correctly if you set $word-Visible to 1: try { $word = new COM('word.application'); $word->Visible = 0; $word->Documents->Open("C:\\test.doc"); echo "Number of pages: " . $word->ActiveDocument->ActiveWindow->ActivePane->Pages->Count() . "</br>"; $i = 1; foreach ($word->ActiveDocument->ActiveWindow->ActivePane->Pages as $page) { echo "Page number: $i </br>"; $i++; } //get the EMF image of the page $data = $word->ActiveDocument->ActiveWindow->ActivePane->Pages->Item(3)->EnhMetaFileBits; $word->ActiveDocument->Close(); $word->Quit(); } catch (Exception $e) { echo "Exception: " .$e->getMessage(); } The test document I'm using contains 35 pages. The code will display the correct number of pages but the for each loop only loops over 1 page. I can only directly access page 1 and 2 in the Pages-Item() collection. If I try to access another page I get the exception: "The requested member of the collection does not exist." If I set the $word-Visible property to 1 I do get all the pages in the foreach loop and I can access any page directly. Everything is working as expected if Word is set to be visible. Even stranger is the fact that if I set Word to be invisible and I don't have the foreach loop I can only access page 1 instead of page 1 and 2 if I do the for each loop. Any pointers on how I can access all the pages in the document and keeping word invisible?

    Read the article

  • Oracle Data Provider and casting

    - by mrjoltcola
    I use Oracle's specific data provider, not the Microsoft provider that is being discontinued. The thing I've found about ODP.NET is how picky it is with data types. Where JDBC and other ADO providers just convert and make things work, ODP.NET will throw an invalid cast exception unless you get it exactly right. Consider this code: String strSQL = "SELECT DOCUMENT_SEQ.NEXTVAL FROM DUAL"; OracleCommand cmd = new OracleCommand(strSQL, conn); reader = cmd.ExecuteReader(); if (reader != null && reader.Read()) { Int64 id = reader.GetInt64(0); return id; } Due to ODP.NET's pickiness on conversion, this doesn't work. My usual options are: 1) Retrieve into a Decimal and return it with a cast to an Int64 (I don't like this because Decimal is just overkill, and at least once I remember reading it was deprecated...) Decimal id = reader.GetDecimal(0); return (Int64)id; 2) Or cast in the SQL statement to make sure it fits into Int64, like NUMBER(18) String strSQL = "SELECT CAST(DOCUMENT_SEQ.NEXTVAL AS NUMBER(18)) FROM DUAL"; I do (2), because I feel its just not clean pulling a number into a .NET Decimal when my domain types are Int32 or Int64. Other providers I've used are nice (smart) enough to do the conversion on the fly. Any suggestions from the ODP.NET gurus?

    Read the article

  • django: grouping in an order_by query?

    - by AP257
    Hi all, I want to allocate rankings to users, based on a points field. Easy enough you'd think with an order_by query. But how do I deal with the situation where two users have the same number of points and need to share the same ranking? Should I use annotate to find users with the same number of points? My current code, and a pseudocode description of what I'd like to do, are below. top_users = User.objects.filter(problem_user=False).order_by('-points_total') # Wrong - in pseudocode, this should be # Get the highest points_total, find all the users with that points_total, # if there is more than one user, set status to 'Joint first prize', # otherwise set status to 'First prize' top_users[0].status = "First prize" if (top_users[1]): top_users[1].status = "Second prize" if (top_users[2]): top_users[2].status = "Third prize" if (top_users[3]): top_users[3:].status = "Highly commended" The code above doesn't deal with the situation where two users have the same number of points and need to share second prize. I guess I need to create a query that looks for unique values of points_total, and does some kind of nested ranking? It also doesn't cope with the fact that sometimes there are fewer than 4 users - does anyone know how I can do (in pseudocode) 'if top_users[1] is not null...' in Python?

    Read the article

  • Average performance of binary search algorithm?

    - by Passionate Learner
    http://en.wikipedia.org/wiki/Binary_search_algorithm#Average_performance BinarySearch(int A[], int value, int low, int high) { int mid; if (high < low) return -1; mid = (low + high) / 2; if (A[mid] > value) return BinarySearch(A, value, low, mid-1); else if (A[mid] < value) return BinarySearch(A, value, mid+1, high); else return mid; } If the integer I'm trying to find is always in the array, can anyone help me write a program that can calculate the average performance of binary search algorithm? I know I can do this by actually running the program and counting the number of calls, but what I'm trying to do here is to do it without calling the function. I'm not asking for a time complexity, I'm trying to calculate the average number of calls. For example, the average number of calls to find a integer in A[2], it would be 1.67 (5/3).

    Read the article

  • Converting a PHP associative array to a JSON associative array

    - by Extrakun
    I am converting a look-up table in PHP which looks like this to JavaScript using json_encode: AbilitiesLookup Object ( [abilities:private] => Array ( [1] => Ability_MeleeAttack Object ( [abilityid:protected] => [range:protected] => 1 [name:protected] => MeleeAttack [ability_identifier:protected] => MeleeAttack [aoe_row:protected] => 1 [aoe_col:protected] => 1 [aoe_shape:protected] => [cooldown:protected] => 0 [focusCost:protected] => 0 [possibleFactions:protected] => 2 [abilityDesc:protected] => Basic Attack ) .....snipped... And in JSON, it is: {"1":{"name":"MeleeAttack","fof":"2","range":"1","aoe":[null,"1","1"],"fp":"0","image":"dummy.jpg"},.... The problem is I get a JS object, not an array, and the identifier is a number. I see 2 ways around this problem - either find a way to access the JSON using a number (which I do not know how) or make it such that json_encode (or some other custom encoding functions) can give a JavaScript associative array. (Yes, I am rather lacking in my JavaScript department). Note: The JSON output doesn't match the array - this is because I do a manual json encoding for each element in the subscript, before pushing it onto an array (with the index as the key), then using json_encode on it. To be clear, the number are not sequential because it's an associative array (which is why the JSON output is not an array).

    Read the article

  • Use regular expressions to match an ? but not a \?

    - by J.Milly
    I have a PHP regular expression that has been functioning fairly well to parse some odd legacy client templates until recently when we found an escaped question mark (\?) included in a template expression. I'm not strong enough with my regular expression-fu to wrap my feeble noodle around a negative look ahead or some techno-mumbo-jumbo so, tips or points in the right direction would be greatly appreciated. My PHP: preg_match_all("/\{\{IF (.*)\?(.*):(.*)\}\}/U", $template, $m, PREG_SET_ORDER);

    Read the article

  • XSLT Global count of grouped items

    - by Chris
    Hi there, I have a set of items which i am grouping using the muenchian method using keys. This is working great however when i try to do things with the first x number of items it is doing it on the x number of items in each group rather than across the whole set of results. How would i get the individual position of each item accross the whole collection? <xsl:key name="pictures-by-productid" match="/dsQueryResponse/Rows/Row" use="@ProductId" /> <xsl:template match="/"> <div style="border:1px solid red; float:left;"> <xsl:apply-templates select="/" mode="sub"> </xsl:apply-templates> </div> </xsl:template> and the second template <xsl:template match="/" mode="sub"> <xsl:for-each select="/dsQueryResponse/Rows/Row[count(. | key('pictures-by-productid', @ProductId)[1]) = 1]"> <xsl:for-each select="key('pictures-by-productid', @ProductId)"> <xsl:sort select="@PictureType" /> <div style="float:left; margin:2px;"> <img src="{@ThumbNailUrl}" width="58" /> <br /> Download <xsl:number value="position()" format="1. " /> <xsl:value-of select="." /> </div> </xsl:for-each> </xsl:for-each> </xsl:template> Thanks Chris

    Read the article

  • GRAPH PROBLEM: find an algorithm to determine the shortest path from one point to another in a recta

    - by newba
    I'm getting such an headache trying to elaborate an appropriate algorithm to go from a START position to a EXIT position in a maze. For what is worth, the maze is rectangular, maxsize 500x500 and, in theory, is resolvable by DFS with some branch and bound techniques ... 10 3 4 7 6 3 3 1 2 2 1 0 2 2 2 4 2 2 5 2 2 1 3 0 2 2 2 2 1 3 3 4 2 3 4 4 3 1 1 3 1 2 2 4 2 2 1 Output: 5 1 4 2 Explanation: Our agent looses energy every time he gives a step and he can only move UP, DOWN, LEFT and RIGHT. Also, if the agent arrives with a remaining energy of zero or less, he dies, so we print something like "Impossible". So, in the input 10 is the initial agent's energy, 3 4 is the START position (i.e. column 3, line 4) and we have a maze 7x6. Think this as a kind of labyrinth, in which I want to find the exit that gives the agent a better remaining energy (shortest path). In case there are paths which lead to the same remaining energy, we choose the one which has the small number of steps, of course. I need to know if a DFS to a maze 500x500 in the worst case is feasible with these limitations and how to do it, storing the remaining energy in each step and the number of steps taken so far. The output means the agent arrived with remaining energy= 5 to the exit pos 1 4 in 2 steps. If we look carefully, in this maze it's also possible to exit at pos 3 1 (column 3, row 1) with the same energy but with 3 steps, so we choose the better one. With these in mind, can someone help me some code or pseudo-code? I have troubles working this around with a 2D array and how to store the remaining energy, the path (or number of steps taken)....

    Read the article

  • Porting an IBXpress Interbase 6 app to the current Firebird platform, on Delphi 7?

    - by robsoft
    Just wondering if there are any gotchas to be wary of here. We have a legacy D7 app that we developed several years ago for a client, which uses IBXpress to talk to the open source Interbase 6 build. We're having a number of issues with that platform these days (very slow to connect/start-up on new hardware being the chief one) and the client has okayed spending some time/money moving the database over to Firebird. We really DON'T want to embark upon moving it to D2010 (or D2007 which would be my preference right now) as we figure that we might have to move the database layer from IBXpress to something else to best suit Firebird anyway. And at the end of the day, the client is only looking to lessen the database pain, not overhaul/upgrade/rewrite the app. Given the ancestry of Firebird, is it a fairly painless, well-understood path from IBXpress Interbase 6 to (whatever) with Firebird? We have quite a number of sprocs, triggers (and even datatypes) etc in the existing IB database already (and the client has a number of paying customers all using this platform) so we felt that going to Firebird was more likely to be a smoother move than moving to SQL Express (or another flavour of DB entirely). Note that we're not looking for 'embedded' DB advocacy - in many of our client's customers' installations, the software is used in a multi-user client-server way so keeping that kind of approach is important.

    Read the article

  • Can I build this XPath query dynamically in XSLT?

    - by Martin Doms
    I have a document that looks something like <root> <element> <subelement1 /> <subelement2 /> </element> <element> <subelement2 /> <subelement1 /> </element> </root> In my XSLT sheet in the context of /element[2]/[someNode] I want to get a number that represents the distance of /element[1]/[someNode] (ie, the number of preceding siblings of /element1/[someNode]). For example, in the context of /element[2]/subelement1 I'd like to have some way to get the number 2, the distance from /element[1] to /element[1]/subelement2. I only ever need the distance of the given node name from the first instance of . Intuitively I thought I could construct this like <xsl:variable name="nodename" select="name()" /> <xsl:value-of select="/element[1]/$nodename/preceding-sibling::*" /> but unfortunately this sheet doesn't compile. Is what I'm trying to achieve possible in XSLT?

    Read the article

  • Advice welcomed on creating my own Swing component

    - by Toto
    Recently I asked which was the best Swing component to bind to a BigDecimal variable (with some particular editing properties). It turns out that none of the standard Swing components suit me completely, nor did the third-party Swing component libraries I've found out there. So I’ve decided to create my own Swing component. Component description: I want to extend JTextField or JFormattedTextField, so my new component can be easily bound to a BigDecimal variable. The component will have customizable scale and length properties. Behavior: When the component is drawn, it shows only the decimal point and space for scale digits to its right. When the component receives focus the caret should be positioned left to the decimal point. As the user types numbers (any other character is ignored) they appear to the left of the caret, only length – scale numbers are accepted, any other number typed is ignored as the integer portion is full. Any time the user types the decimal point the caret moves to the right side of the decimal point. The following numbers typed are shown in the decimal part, only scale numbers are considered any other number typed is ignored as the decimal portion is full. Additionally, thousand separators should appear as the user types numbers left to the decimal point. Invoking a getValue() method on the component should yield the BigDecimal representing the number just entered. I’ve never created my own Swing component; I’ve barely used the standard ones. So I would appreciate any good tutorial/info/tip on creating the component described. This is the only thing I've got so far. Thanks in advance.

    Read the article

  • Readability and IF-block brackets: best practice

    - by MasterPeter
    I am preparing a short tutorial for level 1 uni students learning JavaScript basics. The task is to validate a phone number. The number must not contain non-digits and must be 14 digits long or less. The following code excerpt is what I came up with and I would like to make it as readable as possible. if ( //set of rules for invalid phone number phoneNumber.length == 0 //empty || phoneNumber.length > 14 //too long || /\D/.test(phoneNumber) //contains non-digits ) { setMessageText(invalid); } else { setMessageText(valid); } A simple question I can not quite answer myself and would like to hear your opinions on: How to position the surrounding (outermost) brackets? It's hard to see the difference between a normal and a curly bracket. Do you usually put the last ) on the same line as the last condition? Do you keep the first opening ( on a line by itself? Do you wrap each individual sub-condition in brackets too? Do you align horizontally the first ( with the last ), or do you place the last ) in the same column as the if? Do you keep ) { on a separate line or you place the last ) on the same line with the last sub-condition and then place the opening { on a new line? Or do you just put the ) { on the same line as the last sub-condition? Community wiki. EDIT Please only post opinions regarding the usage and placement of brackets. The code needs not be re-factored. This is for people who have only been introduced to JavaScript a couple of weeks ago. I am not asking for opinions how to write the code so it's shorter or performs better. I would only like to know how do you place brackets around IF-conditions.

    Read the article

  • How to change one Button background in a gridview? -- Android

    - by Tstop Studios
    I have a GridView with 16 ImageView buttons. My program makes a random number and when the user clicks a button in the gridview, i want it to take the random number (0-15) and set the background of the tile with the same position as the random number (0-15) to a different image. How can I just change one of the buttons background? Here's my code so far: public class ButtonHider extends Activity { Random random = new Random(); int pos; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.button_hider); pos = random.nextInt(15); GridView gridview = (GridView) findViewById(R.id.gvBH); gridview.setAdapter(new ImageAdapter(this)); gridview.setOnItemClickListener(new OnItemClickListener() { public void onItemClick(AdapterView<?> parent, View v, int position, long id) { pos = random.nextInt(16); if (position == pos) { Toast.makeText(ButtonHider.this, "Found Me!", Toast.LENGTH_SHORT).show(); } else { Toast.makeText(ButtonHider.this, "Try Again!!", Toast.LENGTH_SHORT).show(); } } }); } public class ImageAdapter extends BaseAdapter { private Context mContext; public ImageAdapter(Context c) { mContext = c; } public int getCount() { return 16; } public Object getItem(int position) { return null; } public long getItemId(int position) { return 0; } // create a new ImageView for each item referenced by the Adapter public View getView(int position, View convertView, ViewGroup parent) { ImageView imageView; if (convertView == null) { // if it's not recycled, initialize some // attributes imageView = new ImageView(mContext); imageView.setLayoutParams(new GridView.LayoutParams(100, 100)); imageView.setScaleType(ImageView.ScaleType.CENTER_CROP); imageView.setPadding(15, 15, 15, 15); } else { imageView = (ImageView) convertView; } imageView.setImageResource(R.drawable.bh_b); return imageView; } } }

    Read the article

  • PHP - Database schema: version control, branching, migrations.

    - by Billiam
    I'm trying to come up with (or find) a reusable system for database schema versioning in php projects. There are a number of Rails-style migration projects available for php. http://code.google.com/p/mysql-php-migrations/ is a good example. It uses timestamps for migration files, which helps with conflicts between branches. General problem with this kind of system: When development branch A is checked out, and you want to check out branch B instead, B may have new migration files. This is fine, migrating to newer content is straight forward. If branch A has newer migration files, you would need to migrate downwards to the nearest shared patch. If branch A and B have significantly different code bases, you may have to migrate down even further. This may mean: Check out B, determine shared patch number, check out A, migrate downwards to this patch. This must be done from A since the actual applied patches are not available in B. Then, checkout branch B, and migrate to newest B patch. Reverse process again when going from B to A. Proposed system: When migrating upwards, instead of just storing the patch version, serialize the whole patch in database for later use, though I'd probably only need the down() method. When changing branches, compare patches that have been run to patches that are available in the destination branch. Determine nearest shared patch (or oldest difference, maybe) between db table of run patches and patches in destination branch by ID or hash. Could also look for new or missing patches that are buried under a number of shared patches between the two branches. Automatically merge down to the nearest shared patch, using the db table stored down() methods, and then merge up to the branche's latest patch. My question is: Is this system too crazy and/or fraught with consequences to bother developing? My experience with database schema versioning is limited to PHP autopatch, which is an up()-only system requiring filenames with sequential IDs.

    Read the article

  • event flow in action script 3

    - by Shay
    i try to dispatch a custom event from some component on the stage and i register other component to listen to it but the other component doesn't get the event here is my code what do i miss public class Main extends MovieClip //main document class { var compSource:Game; var compMenu:Menu; public function Main() { compSource = new Game; compMenu = new Menu(); var mc:MovieClip = new MovieClip(); addChild(mc); mc.addChild(compSource); // the source of the event - event dispatch when clicked btn mc.addChild(compMenu); //in init of that Movie clip it add listener to the compSource events } } public class Game extends MovieClip { public function Game() { btn.addEventListener(MouseEvent.CLICK, onFinishGame); } private function onFinishGame(e:MouseEvent):void { var score:Number = Math.random() * 100 + 1; dispatchEvent(new ScoreChanged(score)); } } public class Menu extends MovieClip { //TextField score public function Menu() { addEventListener(Event.ADDED_TO_STAGE, init); } private function init(e:Event):void { removeEventListener(Event.ADDED_TO_STAGE, init); //on init add listener to event ScoreChanged addEventListener(ScoreChanged.SCORE_GAIN, updateScore); } public function updateScore(e:ScoreChanged):void { //it never gets here! tScore.text = String(e._score); } } public class ScoreChanged extends Event { public static const SCORE_GAIN:String = "SCORE_GAIN"; public var _score:Number; public function ScoreChanged( score:Number ) { trace("new score"); super( SCORE_GAIN, true); _score = score; } } I don't want to write in Main compSource.addEventListener(ScoreChanged.SCORE_GAIN, compMenu.updateScore); cause i dont want the the compSource will need to know about compMenu its compMenu responsibility to know to what events it needs to listen.... any suggestions? Thanks!

    Read the article

  • Bitwise Operations -- Arithmetic Operations..

    - by RBA
    Hi, Can you please explain the below lines, with some good examples. A left arithmetic shift by n is equivalent to multiplying by 2n (provided the value does not overflow), while a right arithmetic shift by n of a two's complement value is equivalent to dividing by 2n(2 to the power n) and rounding toward negative infinity. If the binary number is treated as ones' complement, then the same right-shift operation results in division by 2n and rounding toward zero. Thankx..

    Read the article

  • How to get position of parent element - XSL

    - by joe
    What I wish I could do in xsl is the following, but unfortunatly parent/position() is not valid. XSL <xsl:template match="li"> <bullet> <xsl:apply-templates/> </bullet> <!-- todo: if this is the last bullet AND there are no more "p" tags, output footer --> <xsl:if test="count(ancestor::div/*) = parent/position()"> <footer/> </xsl:if> </xsl:template> XML <html> <div> <p>There is an x number of me</p> <p>There is an x number of me</p> <p>There is an x number of me</p> <ul> <li>list item</li> <li>list item</li> <li>list item</li> <li>list item</li> <li>list item</li> </ul> </div> </html> Anyone have any ideas how to figure out this problem from WITHIN my template match for li? Thanks!

    Read the article

  • How CPU finds ISR and distinguishes between devices

    - by ripunjay-tripathi-gmail-com
    I should first share all what I know - and that is complete chaos. There are several different questions on the topic, so please don't get irritated :). 1) To find an ISR, CPU is provided with a interrupt number. In x86 machines (286/386 and above) there is a IVT with ISRs in it; each entry of 4 bytes in size. So we need to multiply interrupt number by 4 to find the ISR. So first bunch of questions is - I am completely confused in mechanism of CPU receiving the interrupt. To raise an interrupt, firstly device shall probe for IRQ - then what ? The interrupt number travels "on IRQ" towards CPU? I also read something like device putting ISR address on data bus ; whats that then ? What is the concept of devices overriding the ISR. Can somebody tell me few example devices where CPU polls for interrupts? And where does it finds ISR for them ? 2) If two devices share an IRQ (which is very much possible), how does CPU differs amongst them ? What if both devices raise an interrupt of same priority simultaneously. I got to know there will be masking of same type and low priority interrupts - but how this communication happens between CPU and device controller? I studied the role of PIC and APIC for this problem, but could not understand. Thanks for reading. Thank you very much for answering.

    Read the article

  • average case running time of linear search algorithm

    - by Brahadeesh
    Hi all. I am trying to derive the average case running time for deterministic linear search algorithm. The algorithm searches an element x in an unsorted array A in the order A[1], A[2], A[3]...A[n]. It stops when it finds the element x or proceeds until it reaches the end of the array. I searched on wikipedia and the answer given was (n+1)/(k+1) where k is the number of times x is present in the array. I approached in another way and am getting a different answer. Can anyone please give me the correct proof and also let me know whats wrong with my method? E(T)= 1*P(1) + 2*P(2) + 3*P(3) ....+ n*P(n) where P(i) is the probability that the algorithm runs for 'i' time (i.e. compares 'i' elements). P(i)= (n-i)C(k-1) * (n-k)! / n! Here, (n-i)C(k-1) is (n-i) Choose (k-1). As the algorithm has reached the ith step, the rest of k-1 x's must be in the last n-i elements. Hence (n-i)C(k-i). (n-k)! is the total number of ways of arranging the rest non x numbers, and n! is the total number of ways of arranging the n elements in the array. I am not getting (n+1)/(k+1) on simplifying.

    Read the article

< Previous Page | 214 215 216 217 218 219 220 221 222 223 224 225  | Next Page >