Search Results

Search found 7643 results on 306 pages for 'magic numbers'.

Page 35/306 | < Previous Page | 31 32 33 34 35 36 37 38 39 40 41 42  | Next Page >

  • Fibonacci Numbers in Haskell

    - by boraer
    Hi everbody I need to change my F# code to Haskell code but I am so new in Haskell and I can not this My code simply read data from keyboard if data not an integer return an error message then calculate the n fibonacci number then writes to a list after that writes the list into a txt file Here is my code open System let rec fib n = match n with |0->0 |1->1 |2->1 |n->fib(n-1)+fib(n-2);; let printFibonacci list = for i=0 to (List.length list)-1 do printf "%d " (list.Item(i));; let writeToFile list = let file = System.IO.File.Create("C:\out2.txt") let mutable s ="" let writer = new System.IO.StreamWriter(file) try for i=0 to (List.length list)-1 do s <- list.Item(i).ToString() writer.Write(s+" ") finally writer.Close() file.Dispose() printfn "Writed To File" let mutable control = true let mutable num = 0 while control do try printfn "Enter a Number:" num <- Convert.ToInt32(stdin.ReadLine()) let listFibonacci = [for i in 0 .. num-1->fib(i)] printFibonacci(listFibonacci) printfn "\n%A"(listFibonacci) writeToFile(listFibonacci) control<-false with | :? System.FormatException->printfn "Number Format Exception"; Console.ReadKey true|>ignore

    Read the article

  • Math Mod Containing Numbers

    - by TheDarkIn1978
    i would like to write a simple line of code, without resorting to if statements, that would evaluate whether a number is within a certain range. i can evaluate from 0 - Max by using the modulus. 30 % 90 = 30 //great however, if the test number is greater than the maximum, using modulus will simply start it at 0 for the remaining, where as i would like to limit it to the maximum if it's past the maximum 94 % 90 = 4 //i would like answer to be 90 it becomes even more complicated, to me anyway, if i introduce a minimum for the range. for example: minimum = 10 maximum = 90 therefore, any number i evaluate should be either within range, or the minimum value if it's below range and the maximum value if it's above range -76 should be 10 2 should be 10 30 should be 30 89 should be 89 98 should be 90 23553 should be 90 is it possible to evaluate this with one line of code without using if statements?

    Read the article

  • ms access negative page numbers

    - by FrustratedWithFormsDesigner
    I have an access report that generates 36505 pages (un filtered, and about half of each page is taken up by group headers and page headers) , though the footer at the bottom of the report page says "36505 of -29031". This looks like an overflow problem maybe, though I'm confused how it got the current page number of the last page OK, but failed to get total page count. Has anyone dealt with this before?

    Read the article

  • Using write to print floating point numbers.

    - by Tom
    Hi, As an exercise to achieve something larger, i'm trying to use write to print a floating point number. I haven't done this in a while. I must be doing something wrong because I cant get it to work. Here is my code #include <unistd.h> int main(){ float f = 4.5; write(1,&f,sizeof float); return 0; } However, when running it im getting ?@ Any thoughts? Thanks in advance.

    Read the article

  • Using system time directly to get random numbers

    - by Richard Mar.
    I had to return a random element from an array so I came up with this placeholder: return codes[(int) (System.currentTimeMillis() % codes.length - 1)]; Now than I think of it, I'm tempted to use it in real code. The Random() seeder uses system time as seed in most languages anyway, so why not use that time directly? As a bonus, I'm free from the worry of non-random lower bits of many RNGs. It this hack coming back to bite me? (The language is Java if that's relevant.)

    Read the article

  • PHP Game weapon accuracy

    - by noko
    I'm trying to come up with a way for players to fire their weapons and only hit for a certain percentage. For example, one gun can only hit 70% of the time while another only hits 34% of the time. So far all I could come up with is weighted arrays. Attempt 1: private function weighted_random(&$weight) { $weights = array(($weight/100), (100-$weight)/100); $r = mt_rand(1,1000); $offset = 0; foreach($weights as $k => $w) { $offset += $w*1000; if($r <= $offset) return $k; } } Attempt 2: private function weapon_fired(&$weight) { $hit = array(); for($i = 0; $i < $weight; $i++) $hit[] = true; for($i = $weight; $i < 100; $i++) $hit[] = false; shuffle($hit); return $hit[mt_rand(0,100)]; } It doesn't seem that the players are hitting the correct percentages but I'm not really sure why. Any ideas or suggestions? Is anything glaringly wrong with these? Thanks

    Read the article

  • power and modulo on the fly for big numbers

    - by user unknown
    I raise some basis b to the power p and take the modulo m of that. Let's assume b=55170 or 55172 and m=3043839241 (which happens to be the square of 55171). The linux-calculator bc gives the results (we need this for control): echo "p=5606;b=55171;m=b*b;((b-1)^p)%m;((b+1)^p)%m" | bc 2734550616 309288627 Now calculating 55170^5606 gives a somewhat large number, but since I have to do a modulooperation, I can circumvent the usage of BigInt, I thought, because of: (a*b) % c == ((a%c) * (b%c))%c i.e. (9*7) % 5 == ((9%5) * (7%5))%5 => 63 % 5 == (4 * 2) %5 => 3 == 8 % 5 ... and a^d = a^(b+c) = a^b * a^c, therefore I can divide b+c by 2, which gives, for even or odd ds d/2 and d-(d/2), so for 8^5 I can calculate 8^2 * 8^3. So my (defective) method, which always cut's off the divisor on the fly looks like that: def powMod (b: Long, pot: Int, mod: Long) : Long = { if (pot == 1) b % mod else { val pot2 = pot/2 val pm1 = powMod (b, pot, mod) val pm2 = powMod (b, pot-pot2, mod) (pm1 * pm2) % mod } } and feeded with some values, powMod (55170, 5606, 3043839241L) res2: Long = 1885539617 powMod (55172, 5606, 3043839241L) res4: Long = 309288627 As we can see, the second result is exactly the same as the one above, but the first one looks quiet different. I'm doing a lot of such calculations, and they seem to be accurate as long as they stay in the range of Int, but I can't see any error. Using a BigInt works as well, but is way too slow: def calc2 (n: Int, pri: Long) = { val p: BigInt = pri val p3 = p * p val p1 = (p-1).pow (n) % (p3) val p2 = (p+1).pow (n) % (p3) print ("p1: " + p1 + " p2: " + p2) } calc2 (5606, 55171) p1: 2734550616 p2: 309288627 (same result as with bc) Can somebody see the error in powMod?

    Read the article

  • Initializing a C++ vector to random values... fast

    - by Flamewires
    Hey, id like to make this as fast as possible because it gets called A LOT in a program i'm writing, so is there any faster way to initialize a C++ vector to random values than: double range;//set to the range of a particular function i want to evaluate. std::vector<double> x(30, 0.0); for (int i=0;i<x.size();i++) { x.at(i) = (rand()/(double)RAND_MAX)*range; } EDIT:Fixed x's initializer.

    Read the article

  • PHP Fatal error on line number that doesn't exist

    - by alexantd
    Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 523800 bytes) in /Library/WebServer/Documents/XMLDataStore.class.php on line 981 The curious thing about this error is not the memory leak, which would be easy enough to troubleshoot. Rather, it is the fact that XMLDataStore.class.php is only 850 lines long, which I have verified in multiple text editors. This is with the PHP 5.3 bundled with Snow Leopard. I'm not using an opcode cache. Here is my php.ini: allow_url_fopen = Off error_reporting = -1 display_errors = 1 display_startup_errors = 1 date.timezone = 'America/Los_Angeles' output_buffering = Off realpath_cache_size = 0k XMLDataStore.class.php has recently been refactored and it used to be longer than 981 lines. It's almost as if PHP has cached a 2-week-old version and is reading that. I'm positive that the current version at /Library/WebServer/Documents/XMLDataStore.class.php is only 850 lines long, though.

    Read the article

  • using empty on inaccessible object with __isset and __get

    - by David
    <?php class Magic_Methods { protected $meta; public function __construct() { $this->meta = (object) array( 'test' => 1 ); } public function __isset($name) { echo "pass isset {$name} \n"; return isset($this->$name); } public function __get($name) { echo "pass get {$name} \n"; return $this->$name; } } $mm = new Magic_Methods(); $meta = empty($mm->meta->notExisting); var_dump($meta); echo "||\n"; $meta = empty($mm->meta); var_dump($meta); The snippet above does not work as expected for me. Why would the first empty() ommit the __isset? I get this: pass get meta bool(true) || pass isset meta pass get meta bool(false) I would expected identical results or another pass at the __isset, but not a direct call to __get. Or am I missing something here?

    Read the article

  • MySQL SELECT WHERE returning empty with long numbers, although they are there

    - by brybam
    Alright, so basically the most simple query ever... I've done this a million times... SELECT * FROM purchased_items WHERE uid = '$uid' if $uid == 123 It works fine and returns all data in rows where uid is 123 if $uid == 351565051447743 It returns empty... I'm positive 351565051447743 is a possible uid in some rows, i literally copied and pasted it into the table. $uid is a string, and is being passed as a string. This is something i've done a million times, and i've never had this simple query not work. Any ideas why this is not working?

    Read the article

  • Looking for industry numbers on source code management

    - by Dave Duchene
    I'm looking for statistics on SCM usage, in particular I'm trying to find out what percentage of their time developers spend on SCM-related tasks. The more detailed the breakdown, the better. Online and offline resources would both be tremendously useful to me. Can anyone point me towards some industry studies? Preferably recent ones?

    Read the article

  • Disk IO Performance Limitations based on numbers of folders/files

    - by Josh
    I have an application where users are allowed to upload images to the server. Our Web Server is a windows 2008 server and we have a site (images.mysite.com) that points to a shared drive on a unix box. The code used to do the uploading is C# 3.5. The system currently supports a workflow where after a threshold is met a new subfolder can be generated. The question we have is how many files and/or subfolders can you have in a single folder before there is a degredation in performance - in serving the images up through IIS 7 and reading/writing through code?

    Read the article

  • .NET - alpha-numeric representation of numbers

    - by mack369
    I'm implementing serial key functionality in my application. User needs to enter at least 64bit number in order to register the application. Because typing number like 9,223,372,036,854,775,807 will take a while I want to compress it a bit. The first guess was to code this number hexadecimally but it still is quite long (0x7FFF FFFF FFFF FFFF). Is there any standard method in .NET to code this number alphanumerically using for example: digits, upper-case and lower-case characters?

    Read the article

  • RSpec: in-depth differences between before(:all) and before(:each)

    - by gmile
    Ok, so I've ran into a very strange issue, directly connected with before blocks. I'm doing a integration testing via Watir and RSpec. For a simple test to check if user can perform a login I'm creating a 'user' record in the db by means of factory_girl. So I put the following code: before(:each) do @user = Factory(:user) end if "should perform a login" do # do stuff end In do stuff I call a browser and see how the user tries to login. Unfortunately, somehow he cannot do that — "Username isn't valid". After some investigation I discovered that if I put the code for creating user in before(:all) block, everything magically works. How's that? What's the difference between :all and :each in this context? Also, If I put the code for creating user actually in the test body, it still doesn't work (i.e. user somehow isn't added to the DB or something).

    Read the article

< Previous Page | 31 32 33 34 35 36 37 38 39 40 41 42  | Next Page >