Search Results

Search found 491 results on 20 pages for 'rand'.

Page 14/20 | < Previous Page | 10 11 12 13 14 15 16 17 18 19 20  | Next Page >

  • Declaring a C function to return an array

    - by Jaska
    How can I make a function which returns an array? I tried this const int WIDTH=11; const int HEIGHT=11; int main() { char A[WIDTH][HEIGHT]; A=rand_grid(WIDTH,HEIGHT); return 0; } // Initializes a random board. char[][] rand_grid(int i, int k) { char* A[i][k]; for(j=0;j<i;++j) { for(l=0;l<k;++l) { A[j][l]=ran(10); } } return A; } // Returns a random number from the set {0,...,9}. int ran(int i) { srand((unsigned int) time(0)); return(rand()%10); }

    Read the article

  • c++ new & delete and string & functions

    - by Newbie
    Okay the previous question was answered clearly, but i found out another problem. What if i do: char *test(int ran){ char *ret = new char[ran]; // process... return ret; } And then run it: for(int i = 0; i < 100000000; i++){ string str = test(rand()%10000000+10000000); // process... // no need to delete str anymore? string destructor does it for me here? } So after converting the char* to string, i dont have to worry about the deleting anymore?

    Read the article

  • How to make a file_exist from a server to the local machine ?

    - by bahamut100
    Hi, how to test if a file exist on the current computer using the application ? I try to put the full url at my file like this, but it doesn't work : if(file_exists("C:/wamp/www/project/photo/".$nom_photo)) { echo "file exist"; $extension=pathinfo("C:/wamp/www/project/photo/".$nom_photo,PATHINFO_EXTENSION); echo "<br>"; $nom=md5($nom_photo.time().rand(0, 99999)).".".$extension; echo $nom; rename("C:/wamp/www/project/photo/".$nom_photo,"C:/wamp/www/project/photo/".$nom); echo "<br>"; } How to fix it ?

    Read the article

  • Meaning of tA tC and tP

    - by Greg Wiley
    If this is a duplicate I appoligize, but looking for two-letter strings is quite hard in any search. I'm looking for the meaning of tA tC and tP in the context of a mysql query. And in the spirit of "teaching a man how to fish" it would be great if you could point me in the right direction of where to find this info in the future. Edit: The Query $wpdb->get_row($wpdb->prepare("SELECT tA.* FROM ".AMYLITE_ADS." tA, ".AMYLITE_ADS_CAMPAIGNS." tC, ".AMYLITE_PACKAGES." tP WHERE tA.id=tC.ad_id AND tC.campaign_id=tP.campaign_id AND tP.zone_id=%d AND tP.date_end>CURDATE() GROUP BY tA.id ORDER BY RAND()", $zone->id));

    Read the article

  • Mutual Information / Entropy Calculation Help

    - by Fillip
    Hi, Hoping someone can give me some pointers with this entropy problem. Say X is chosen randomly from the uniform integer distribution 0-32 (inclusive). I calculate the entropy, H(X) = 32 bits, as each Xi has equal probability of occurring. Now, say the following pseudocode executes. int r = rand(0,1); // a random integer 0 or 1 r = r * 33 + X; How would I work out the mutual information between the two variables r and X? Mutual Information is defined as I(X; Y) = H(X) - H(X|Y) but I don't really understand how to apply the conditional entropy H(X|Y) to this problem. Thanks

    Read the article

  • failed to open stream: HTTP request failed! HTTP/1.1 400 Bad Request

    - by muralikalpana
    I am accessing images from another website. I am getting "failed to open stream: HTTP request failed! HTTP/1.1 400 Bad Request " error when copying 'some(not all)' images. here is my code. $img=$_GET['img']; //another website url $file=$img; function getFileextension($file) { return end(explode(".", $file)); } $fileext=getFileextension($file); if($fileext=='jpg' || $fileext=='gif' || $fileext=='jpeg' || $fileext=='png' || $fileext=='x-png' || $fileext=='pjpeg'){ if($img!=''){ $rand_variable1=rand(10000,100000); $node_online_name1=$rand_variable1."image.".$fileext; $s=copy($img,"images/".$node_online_name1); }

    Read the article

  • How do I request a single random row from a force.com database in SOQL?

    - by Ollie C
    Total row-count is in the range 10k-100k rows. Can I use RAND() on force.com? Unfortunately although all the rows have a unique numeric identifier, there are many gaps, and I'd often want to select a random row from a filtered subset anyway. I suspect there's no particularly efficient way to do this, but is it possible at all? Ultimately all I want to do is to extract one row from a table (or a subset based on specific filter criteria) at random. If force.com doesn't let me select a random row, then can I query the rows to select from, and assign sequential IDs to all the rows, say 1-1,035, and then select a random number in that range locally, say 349, and then get row 349?

    Read the article

  • Is there anyone out there that codes like me?

    - by Jacob Relkin
    Hi, Some people have told me that my coding style is a lot different than theirs. I think I am somewhat neurotic when it comes to spacing and indenting though. Here's a snippet to show you what I mean: - ( void ) applicationDidFinishLaunching: ( UIApplication *) application { SomeObject *object = [ [ SomeObject alloc ] init ]; int x = 100 / 5; object.someInstanceVariable = ( ( 4 * x ) + rand() ); [ object someMethod ]; } Notice how I space out all of my brackets/parentheses, start curly braces on the same line, "my code has room to breathe", so to speak. So my questions are a) is this normal and b) What's your coding style?

    Read the article

  • [PHP] md5(uniqid) makes sense for random unique tokens?

    - by Exception e
    I want to create a token generator that generates tokens that cannot be guessed by the user and that are still unique (to be used for password resets and confirmation codes). I often see this code; does it make sense? md5(uniqid(rand(), true)); According to a comment uniqid($prefix, $moreEntopy = true) yields first 8 hex chars = Unixtime, last 5 hex chars = microseconds. I don't know how the $prefix-parameter is handled.. So if you don't set the $moreEntopy flag to true, it gives a predictable outcome. QUESTION: But if we use uniqid with $moreEntopy, what does hashing it with md5 buy us? Is it better than: md5(mt_rand())

    Read the article

  • Select 2 Rows from Table when COUNT of another table

    - by Marcus
    Here is the code that I currently have: SELECT `A`.* FROM `A` LEFT JOIN `B` ON `A`.`A_id` = `B`.`value_1` WHERE `B`.`value_2` IS NULL AND `B`.`userid` IS NULL ORDER BY RAND() LIMIT 2 What it currently is supposed to do is select 2 rows from A when the 2 rows A_id being selected are not in value_1 or value_2 in B. And the rows in B are specific to individual users with userid. What I need to do is make it also so that also checks if there are already N rows in B matching a A_id (either in value_1, or value_2) and userid, and if there are more than N rows, it doesn't select the A row.

    Read the article

  • How to make code run a certain amount of times before returning something?

    - by user3564967
    I made a trivia game and I have to make a method (SuccessOrFail) that will return whether the user beat the trivia or not. namespace D4 { /// <summary> /// Displays the trivia and returns whether the user succeeded or not, number of questions asked, and a free piece of trivia. /// </summary> public partial class TriviaForm : Form { private Trivia trivia; private Question question; private Random rand = new Random(); private HashSet<int> pickedQuestion = new HashSet<int>(); private string usersAnswer; private int numCorrectAnswers; private int numIncorrectAnswers; public TriviaForm() { InitializeComponent(); this.trivia = new Trivia(); QuestionRandomizer(); QuestionOutputter(); } /// <summary> /// This method will return true if succeeded or false if not. /// </summary> /// <returns>Whether the user got the trivia right or not</returns> public bool SuccessOrFail(bool wumpus) { bool successOrFail = false; int maxQuestions = 3; if (wumpus == true) maxQuestions = 5; int numNeededCorrect = maxQuestions / 2 + 1; if (this.usersAnswer == question.CorrectAnswer.ToString()) numCorrectAnswers++; else numIncorrectAnswers++; if (numCorrectAnswers + numIncorrectAnswers == maxQuestions) { if (numCorrectAnswers == numNeededCorrect) successOrFail = true; else successOrFail = false; numCorrectAnswers = 0; numIncorrectAnswers = 0; return successOrFail; } else return false; } /// <summary> /// This method will output a free answer to the player. /// </summary> public string FreeTrivia() { return question.Freetrivia; } // This method tells the player whether they were correct or not. private void CorrectOrNot() { if (this.usersAnswer == question.CorrectAnswer.ToString()) MessageBox.Show("Correct"); else MessageBox.Show("Incorrect"); } // Displays the questions and answers on the form. private void QuestionOutputter() { this.txtQuestion.Text = question.QuestionText; this.txtBox0.Text = question.Answers[0]; this.txtBox1.Text = question.Answers[1]; this.txtBox2.Text = question.Answers[2]; this.txtBox3.Text = question.Answers[3]; } // Clears the TextBoxes and displays a new random question. private void btnNext_Click(object sender, EventArgs e) { this.usersAnswer = txtAnswer.Text; CorrectOrNot(); this.txtQuestion.Clear(); this.txtBox0.Clear(); this.txtBox1.Clear(); this.txtBox2.Clear(); this.txtBox3.Clear(); this.txtAnswer.Clear(); this.txtAnswer.Focus(); QuestionRandomizer(); QuestionOutputter(); this.txtsuc.Text = SuccessOrFail(false).ToString(); } // Choose a random number and assign the corresponding data to question, refreshes the list if all questions used. private void QuestionRandomizer() { if (pickedQuestion.Count < trivia.AllQuestions.Count) { int random; do { random = rand.Next(trivia.AllQuestions.Count); } while (pickedQuestion.Contains(random)); pickedQuestion.Add(random); this.question = trivia.AllQuestions.ToArray()[random]; if (pickedQuestion.Count == trivia.AllQuestions.ToArray().Length) pickedQuestion.Clear(); } } } } My question is how to make it so that the code asks the user 3 or 5 questions and then returns whether the user won or not? I was wondering if somehow I could make a public void that would just make the form pop up and ask the user 3 to 5 questions and then once it asks the maximum number of questions, to close and then have a method that returns true if the user won, or false if they didn't. But I literally have no idea how to do that. Edit: So I know a for loop can make code run more than once. But the problem I'm having is, is that I don't know how to make it so that the trivia game asks 3 to 5 questions BEFORE returning something.

    Read the article

  • How to get some randomized concats based on 2 columns from 1 table?

    - by Nils Riedemann
    Hey folks, i have a large user Database (13k+), and for some reason i need to create random names. The users table has "first_name" and "last_name". Now i want to have 10 concats of full_name and last_name of two completely random rows. Is that even possible with SQL? My other idea was just to create a full_names and last_names table … but that would'nt be as much challenging. Oh, and it should not take up too much performance :) (so order by rand() is not an option ;))

    Read the article

  • MYSQL, Subquery Reference in Union

    - by christian
    Is there any way to reference a subquery in a union? I am trying to do something like the following, and would like to avoid a temporary table, but the subquery will be drawn from a much larger dataset so it makes sense to only do it once.. SELECT * FROM (SELECT * FROM ads WHERE state='FL' AND city='Maitland' AND page='home' ORDER BY RAND()) AS sq WHERE spot = 'full-banner' LIMIT 1 UNION SELECT * FROM sq WHERE spot = 'leaderboard' LIMIT 1 UNION SELECT * FROM sq WHERE spot = 'rectangle1' LIMIT 1 UNION SELECT * FROM sq WHERE spot = 'rectangle2' LIMIT 1 .... etc,, It's a shame that DISTINCT can't be specified for a single column of a result set.

    Read the article

  • Segmentation fault before return

    - by donalmg
    Hi, Why does the following code seg fault before returning: int main() { char iD[20]; memset (iD, 0, 20); char* prefix; srand (time(NULL) ); int iPrefix = rand()%1000000; sprintf(prefix, "%i", iPrefix); int len = strlen(prefix); char* staticChar = "123456789"; //set prefix into ID memcpy(iD, prefix, len); // append static value memcpy(iD+len, staticChar, 20-len); cout << "END " << endl; return 0; } At the minute, the cout will display, but I get a segmentation fault.

    Read the article

  • Looking for a clear and concise web page explaining why lower bits of random numbers are usually not

    - by Hamish Grubijan
    I am putting together an internal "every developer should know" wiki page. I saw many discussions regarding rand() % N, but not a single web page that explains it all. For instance, I am curious if this problem is only C- and Linux-specific, or if it also applies to Windows, C++,. Java, .Net, Python, Perl. Please help me get to the bottom of this. Also, just how non-random do the numbers get? Thank you!

    Read the article

  • jquery ajax form function(data)

    - by RussP
    Can some one please tell me where I have gone wrong. What ever I do I get the answer "no" JQuery to send data to php query $j.post("logincheck.php",{ username:$j('#username').attr('value'), password:$j('#password').attr('value'), rand:Math.random() } , function(data) { if(data=='yes') {alert('yes');} else {alert('no');} } ); Here is the php query if(isset($_POST['username'])): $username = $_POST['username']; $password = $_POST['password']; $posts = mysql_query("SELECT * FROM users WHERE username='$username'"); $no_rows = mysql_num_rows($posts ); while($row = mysql_fetch_array($posts)): print 'yes'; endwhile; else: print 'no'; //header('location: index.php'); endif; endif; Thank in adance

    Read the article

  • How to get the records using order by and so on

    - by paulrajj
    I have a table categories containing categories id having the records of 1 to 20. when i am doing the search query by using the IN function in mysql i got the results. but i am struggling to get the results using order by. The limit may be vary for every search as this is one of the input value. For example I have tried this query to find out the search results, select * from categories where category in (20,16,12,8) order by rand(), id limit 0,6 this query is executed and the results are in random category_id. the results will be, 8 12 16 20 and following this, another two records must be 8 12 If category_id contains only one record for 8 then, it should follow from 12,16. How can i achieve this ? thanks in advance.

    Read the article

  • Problem with xor operation

    - by gavishna
    Kindly tell me why the original image is not coming with this code. The resulting image receive is yellowish in color,instead of being similar to the image Img_new Img=imread(‘lena_color.tif’); Img_new=rgb2gray(img); Send=zeroes(size(Img_new); Receive= zeroes(size(Img_new); Mask= rand(size(Img_new); for i=1 :256 for j=1:256 Send(i,j)=xor( Img_new(i,j),mask(i,j)); End End image(send); imshow(send); for i=1 :256 for j=1:256 receive(i,j)=xor( send(i,j),mask(i,j)); End End image(receive); imshow(receive); plz help

    Read the article

  • unique random id

    - by Piyush
    I am generating unique id for my small application but I am facing some variable scope problem. my code- function create_id() { global $myusername; $part1 = substr($myusername, 0, -4); $part2 = rand (99,99999); $part3 = date("s"); return $part1.$part2.$part3; } $id; $count=0; while($count == 1) { $id; $id=create_id(); $sqlcheck = "Select * FROM ruser WHERE userId='$id';"; $count =mysql_query($sqlcheck,$link)or die(mysql_error()); } echo $id; I dont know which variable I have to declare as global

    Read the article

  • Storing a variable into a database

    - by Alekx
    In an attempt to better learn Rails and I'm building a simple Blackjack game, but I'm running into a problem of storing the variable. I understand how to store user-genereated data into the db using form_for, but I'm struggling to create a random number and put it in the db. @hand = rand(9) + 2 I have "hand" as a field in my db, just curious how to store this random number. Any help anyone could provide to point me in the right direction would be very much appreciated. Thanks.

    Read the article

  • How to fetch a random record from SQLite database?

    - by Bruce
    I am working on PHP. I was working with MySQL before. Here is the code I used - $offset_result = mysqli_query($con, " SELECT FLOOR(RAND() * COUNT(*)) AS `offset` FROM students "); $offset_row = mysqli_fetch_object( $offset_result ); $offset = $offset_row->offset; $result = mysqli_query($con, " SELECT name FROM students LIMIT $offset, 1 " ); $row = mysqli_fetch_row($result); mysqli_free_result($result); What will be the corresponding set of statements for SQLite?

    Read the article

  • C++ function for picking from a list where each element has a distinct probability

    - by Stuart
    I have an array of structs and one of the fields in the struct is a float. I want to pick one of the structs where the probability of picking it is relative to the value of the float. ie struct s{ float probability; ... } sArray s[50]; What is the fastest way to decide which s to pick? Is there a function for this? If I knew the sum of all the probability fields (Note it will not be 1), then could I iterate through each s and compare probability/total_probability with a random number, changing the random number for each s? ie if( (float) (rand() / RAND_MAX) < probability)...

    Read the article

  • MySQL Rating system (calculating average from two tables).

    - by MussuR
    I have two tables, videos and videos_ratings. The videos table has an int videoid field (and many others but those fields are not important I think) and many records. The videos_ratings table has 3 int fields: videoid, rating, rated_by which has many records (multiple records for each fields from the videos table) but not for all records from the videos table. Currently I have the following mysql query: SELECT `videos`.*, avg(`videos_ratings`.`vote`) FROM `videos`, `videos_ratings` WHERE `videos_ratings`.`videoid` = `videos`.`videoid` GROUP BY `videos_ratings`.`videoid` ORDER BY RAND() LIMIT 0, 12 It selects all the records from table videos that have a rating in table video_ratings and calculates the average correctly. But what I need is to select all records from the videos table, no matter if there is a rating for that record or not. And if there aren't any records in the videos_ratings table for that particular videos record, the average function should show 0. Hope someone could understand what I want... :) Thanks!

    Read the article

  • How to ReHash a password stored into my Database ? (PHP)

    - by Vincent Roye
    Hi! I have some passwords encrypted in my database and I would like to find a way to display them. Here is how they are saved into my mysql database: function generateHash($plainText, $salt = null){ if ($salt === null) { $salt = substr(md5(uniqid(rand(), true)), 0, 25); } else { $salt = substr($salt, 0, 25); } return $salt . sha1($salt . $plainText); } $secure_pass = generateHash($this->clean_password); Then $secure_pass is saved into my database. Anyone would have an idea ?? Thank you very much ;)

    Read the article

  • Deterministic random number generator with context?

    - by user653133
    I am looking for a seeded random number generator that creates a pool of numbers as a context. It doesn't have to be too good. It is used for a game, but it is important, that each instance of the Game Engine has it's own pool of numbers, so that different game instances or even other parts of the game that use random numbers don't break the deterministic character of the generated numbers. Currently I am using rand() which obviously doesn't have this feature. Are there any c or objective-c generators that are capable of doing what I want? Best regards, Michael

    Read the article

< Previous Page | 10 11 12 13 14 15 16 17 18 19 20  | Next Page >