Search Results

Search found 592 results on 24 pages for 'digit'.

Page 3/24 | < Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >

  • Enumerating large (20-digit) [probable] prime numbers

    - by Paul Baker
    Given A, on the order of 10^20, I'd like to quickly obtain a list of the first few prime numbers greater than A. OK, my needs aren't quite that exact - it's alright if occasionally a composite number ends up on the list. What's the fastest way to enumerate the (probable) primes greater than A? Is there a quicker way than stepping through all of the integers greater than A (other than obvious multiples of say, 2 and 3) and performing a primality test for each of them? If not, and the only method is to test each integer, what primality test should I be using?

    Read the article

  • find nth digit in C

    - by kokkch
    i spend more than a day to solve this and i can't. I have a function name int get_nth_digit (int x, int pos); which takes as entering the number given by the user(x) and a number that represents the position in which the user wishes to return the item. How can do this with C program? can you help me pls???? thx

    Read the article

  • MatheMagics - Guess My Age Method 1

    - by PointsToShare
    © 2011 By: Dov Trietsch. All rights reserved MatheMagic – Guess My Age – Method 1 The Mathemagician stands on the stage and asks an adult to do the following: ·         Do the next few steps on your calculator, or the calculator in your phone, or even on a piece of paper. ·         Do it silently! Don’t tell me the results until I ask for them directly ·         Compute a single digit multiple of 9 – any one of 9, 18, 27, … all the way to 81, will do. ·         Now multiply your age by 10 ·         Subtract the 9 multiple from this number. ·         Tell me the result. Notice that I don’t know which multiple of 9 you subtracted from 10 times your age. I will nonetheless immediately tell you what your age is. How do I do this? Let’s do the algebra. 10X – 9Y = 10X – 10Y + Y = 10(X – Y) + Y Now remember, you asked an adult, so his/her age is a two digit number (maybe even 3 digits), thus reducing it by the single digit multiplied by nine is still positive – the lowest is can be is 100 – 81 which yields 19. Now make two numbers out of the result. The last digit and the number before it. This number is X – Y or the age minus the single digit you selected. The last digit is this very single digit. This is always so regardless of the digit you selected. So… Add tis digit to the other number and you get back the age! Q.E.D Example: I am 76 years old and here is what happens when I do the steps 76 x 10 = 760 760 – 18 = 742 made of 74 and 2. My age is 74 + 2 760 – 81 = 679 made of 67 and 9. My age is 67 + 9 A note to the socially aware mathemagician – it is safer to do it with a man. The chances of a veracious answer are much, much higher! The trick may be accomplished on any 2 or 3 digit number, not just one’s age, but if you want to know your date’s age, it’s a good way to elicit it. That’s All Folks PS for more Ageless “Age” mathemagics go to www.mgsltns.com/games.htm and also here: http://geekswithblogs.net/PointsToShare/archive/2011/11/15/mathemagics---guess-my-age---method-2.aspx

    Read the article

  • Correct permutation cycle for Verhoeff algorithm

    - by James
    Hello, I'm implementing the Verhoeff algorithm for a check digit scheme, but there seems to be some disagreement in web sources as to which permutation cycle should form the basis of the permutation table. Wikipedia uses: (36)(01589427) while apparently, Numerical Recipies uses a different cycle and this book uses: (0)(14)(23)(56789), quoted from a 1990 article by Winters. It also notes that Verhoeff used the one Wikipedia quotes. Now, my number theory is a little rusty, but the Wikipedia cycle clearly will repeat after the 8th power, while the book one will take 10, despite it saying that s^8=s. Table 2.14(b) has other errors in the 2-cycles, so this is dubious anyway. Unfortunately, I don't have copies of the original articles (and am too tight to pay/disgusted that 40-year old knowledge is still being held to ransom by publishers), nor a copy of Numerical Recipes to check (and am loath to install their paranoia-induced copy protection plug-in to view online). So does any one know which is correct? Are they both correct?

    Read the article

  • Apache FilesMatch regexp: Can it match by the cache buster 10 digit (rails generated) following the filename?

    - by ynkr
    According to the apache FilesMatch docs: The FilesMatch directive provides for access control by filename Basically, I only want to set an expires header for resources that have a 10 digit "cache buster" id appended to the name. So, here is my attempt at such a thing in my httpd.conf <FilesMatch "(jpg|jpeg|png|gif|js|css)\?\d{10}$"> ExpiresActive On ExpiresDefault "now plus 5 minutes" </FilesMatch> And here is an example of a resource I want to match: http://localhost:3000/images/of/elvis/eating-a-bacon-sandwich.png?1306277384 Now obviously my FilesMatch regexp is not matching so I am guessing 1 of 2 things is happening. Either my regexp is wonky or the '?1231231231' cache busting part of the file is not part of what apache considers part of the filename. Can anybody confirm and/or give me a way to cache only those resources that will not persist beyond the next deploy?

    Read the article

  • ASM programming, how to use loop?

    - by chris
    Hello. Im first time here.I am a college student. I've created a simple program by using assembly language. And im wondering if i can use loop method to run it almost samething as what it does below the program i posted. and im also eager to find someome who i can talk through MSN messanger so i can ask you questions right away.(if possible) ok thank you .MODEL small .STACK 400h .data prompt db 10,13,'Please enter a 3 digit number, example 100:',10,13,'$' ;10,13 cause to go to next line first_digit db 0d second_digit db 0d third_digit db 0d Not_prime db 10,13,'This number is not prime!',10,13,'$' prime db 10,13,'This number is prime!',10,13,'$' question db 10,13,'Do you want to contine Y/N $' counter dw 0d number dw 0d half dw ? .code Start: mov ax, @data ;establish access to the data segment mov ds, ax mov number, 0d LetsRoll: mov dx, offset prompt ; print the string (please enter a 3 digit...) mov ah, 9h int 21h ;execute ;read FIRST DIGIT mov ah, 1d ;bios code for read a keystroke int 21h ;call bios, it is understood that the ascii code will be returned in al mov first_digit, al ;may as well save a copy sub al, 30h ;Convert code to an actual integer cbw ;CONVERT BYTE TO WORD. This takes whatever number is in al and ;extends it to ax, doubling its size from 8 bits to 16 bits ;The first digit now occupies all of ax as an integer mov cx, 100d ;This is so we can calculate 100*1st digit +10*2nd digit + 3rd digit mul cx ;start to accumulate the 3 digit number in the variable imul cx ;it is understood that the other operand is ax ;AND that the result will use both dx::ax ;but we understand that dx will contain only leading zeros add number, ax ;save ;variable <number> now contains 1st digit * 10 ;---------------------------------------------------------------------- ;read SECOND DIGIT, multiply by 10 and add in mov ah, 1d ;bios code for read a keystroke int 21h ;call bios, it is understood that the ascii code will be returned in al mov second_digit, al ;may as well save a copy sub al, 30h ;Convert code to an actual integer cbw ;CONVERT BYTE TO WORD. This takes whatever number is in al and ;extends it to ax, boubling its size from 8 bits to 16 bits ;The first digit now occupies all of ax as an integer mov cx, 10d ;continue to accumulate the 3 digit number in the variable mul cx ;it is understood that the other operand is ax, containing first digit ;AND that the result will use both dx::ax ;but we understand that dx will contain only leading zeros. Ignore them add number, ax ;save -- nearly finished ;variable <number> now contains 1st digit * 100 + second digit * 10 ;---------------------------------------------------------------------- ;read THIRD DIGIT, add it in (no multiplication this time) mov ah, 1d ;bios code for read a keystroke int 21h ;call bios, it is understood that the ascii code will be returned in al mov third_digit, al ;may as well save a copy sub al, 30h ;Convert code to an actual integer cbw ;CONVERT BYTE TO WORD. This takes whatever number is in al and ;extends it to ax, boubling its size from 8 bits to 16 bits ;The first digit now occupies all of ax as an integer add number, ax ;Both my variable number and ax are 16 bits, so equal size mov ax, number ;copy contents of number to ax mov cx, 2h div cx ;Divide by cx mov half, ax ;copy the contents of ax to half mov cx, 2h; mov ax, number; ;copy numbers to ax xor dx, dx ;flush dx jmp prime_check ;jump to prime check print_question: mov dx, offset question ;print string (do you want to continue Y/N?) mov ah, 9h int 21h ;execute mov ah, 1h int 21h ;execute cmp al, 4eh ;compare je Exit ;jump to exit cmp al, 6eh ;compare je Exit ;jump to exit cmp al, 59h ;compare je Start ;jump to start cmp al, 79h ;compare je Start ;jump to start prime_check: div cx; ;Divide by cx cmp dx, 0h ;reset the value of dx je print_not_prime ;jump to not prime xor dx, dx; ;flush dx mov ax, number ;copy the contents of number to ax cmp cx, half ;compare half with cx je print_prime ;jump to print prime section inc cx; ;increment cx by one jmp prime_check ;repeat the prime check print_prime: mov dx, offset prime ;print string (this number is prime!) mov ah, 9h int 21h ;execute jmp print_question ;jumps to question (do you want to continue Y/N?) this is for repeat print_not_prime: mov dx, offset Not_prime ;print string (this number is not prime!) mov ah, 9h int 21h ;execute jmp print_question ;jumps to question (do you want to continue Y/N?) this is for repeat Exit: mov ah, 4ch int 21h ;execute exit END Start

    Read the article

  • how to find distinct digit set numbers over a range of integers?

    - by evil.coder
    Suppose i have a unsigned integer, call it low and one another call it high such that highlow. The problem is to find distinct digit set numbers over this range. For example, suppose low is 1 and high is 20 then the answer is 20, because all the numbers in this range are of distinct digit sets. If suppose low is 1 and high is 21, then the answer is 20, because 12 and 21 have same digit set i.e.1, 2. I am not looking for a bruteforce algo., if anyone has a better solution then a usual bruteforce approach, please tell..

    Read the article

  • [Java] Cannot draw pixels

    - by Wilhelm
    Hello everyone. I want to print each digit of pi number as a colored pixel, so, I get na input, with the pi number, then parse it into a list, each node containing a digit (I know, I'll use an array later), but I never get this painted to screen... Can someone help me to see where I'm wrong? package edu.pi.view; import java.awt.Graphics; import java.awt.Image; import java.awt.image.MemoryImageSource; import java.io.BufferedReader; import java.io.File; import java.io.FileReader; import java.util.ArrayList; import java.util.List; import javax.swing.JFrame; import javax.swing.JPanel; public class Main extends JPanel { private static final long serialVersionUID = 6416932054834995251L; private static int pixels[]; private static List<Integer> pi; public static void readFile(String name) { File file = new File(name); BufferedReader reader = null; pi = new ArrayList<Integer>(); char[] digits; try { reader = new BufferedReader(new FileReader(file)); String text = null; while((text = reader.readLine()) != null) { digits = text.toCharArray(); for(char el : digits) if(el != ' ') pi.add(Character.getNumericValue(el)); } } catch (Exception e) { e.printStackTrace(); } } public void paint(Graphics gg) { readFile("c:\\pi.txt"); int h = 5; int w = 2; int color = 0xffffff; int digit; int i = 0; pixels = new int[w * h]; for (int y = 0; y < h; y++) { for (int x = 0; x < h; x++) { digit = pi.get(i); if(digit == 0) color = 0x000000; else if(digit == 1) color = 0x787878; else if(digit == 2) color = 0x008B00; else if(digit == 3) color = 0x00008B; else if(digit == 4) color = 0x008B8B; else if(digit == 5) color = 0x008B00; else if(digit == 6) color = 0xCDCD00; else if(digit == 7) color = 0xFF4500; else if(digit == 8) color = 0x8B0000; else if(digit == 9) color = 0xFF0000; pixels[i] = color; i++; } } Image art = createImage(new MemoryImageSource(w, h, pixels, 0, w)); gg.drawImage(art, 0, 0, this); } public static void main(String[] args) { JFrame frame = new JFrame(); frame.getContentPane().add(new Main()); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(300,300); frame.setVisible(true); } }

    Read the article

  • How to extract digit from the string using regex?

    - by Harikrishna
    I will have a different type of string(string will not have fixed format,they will be different every time) from them I want to remove some specific substring.Like the string can be OPTIDX 26FEB2009 NIFTY CE 2500 OPTIDX NIFTY 30 Jul 2009 4600.00 PE OPTSTK ICICIBANK 30 Jul 2009 700.00 PA I want to extract Rs.(digit) from those string and store it into one variable and then in those string there should not be Rs.(digit). What should be the regex for that to match Rupees ?

    Read the article

  • Good grammar for date data type for recursive descent parser LL(1)

    - by Totophil
    I'm building a custom expression parser and evaluator for production enviroment to provide a limited DSL to the users. The parser itself as the DSL, need to be simple. The parser is going to be built in an exotic language that doesn't support dynamic expression parsing nor has any parser generator tools available. My decision is to go for recursive descent approach with LL(1) grammar, so that even programmers with no previous experience in evaluating expression could quickly learn how the code works. It has to handle mixed expressions made up of several data types: decimals, percentages, strings and dates. And dates in the format of dd/mm/yyyy are easy to confuse with a string of devision ops. Is where a good solution to this problem? My own solution that is aimed at keeping the parser simple involves prefixing dates with a special symbol, let's say apostrophe: <date> ::= <apostr><digit><digit>/<digit><digit>/<digit><digit><digit><digit> <apostr> ::= ' <digit> ::= '0'..'9'

    Read the article

  • Required Working Precision for the BBP Algorithm?

    - by brainfsck
    Hello, I'm looking to compute the nth digit of Pi in a low-memory environment. As I don't have decimals available to me, this integer-only BBP algorithm in Python has been a great starting point. I only need to calculate one digit of Pi at a time. How can I determine the lowest I can set D, the "number of digits of working precision"? D=4 gives me many correct digits, but a few digits will be off by one. For example, computing digit 393 with precision of 4 gives me 0xafda, from which I extract the digit 0xa. However, the correct digit is 0xb. No matter how high I set D, it seems that testing a sufficient number of digits finds an one where the formula returns an incorrect value. I've tried upping the precision when the digit is "close" to another, e.g. 0x3fff or 0x1000, but cannot find any good definition of "close"; for instance, calculating at digit 9798 gives me 0xcde6 , which is not very close to 0xd000, but the correct digit is 0xd. Can anyone help me figure out how much working precision is needed to calculate a given digit using this algorithm? Thank you,

    Read the article

  • Radix Sort in Python [on hold]

    - by Steven Ramsey
    I could use some help. How would you write a program in python that implements a radix sort? Here is some info: A radix sort for base 10 integers is a based on sorting punch cards, but it turns out the sort is very ecient. The sort utilizes a main bin and 10 digit bins. Each bin acts like a queue and maintains its values in the order they arrive. The algorithm begins by placing each number in the main bin. Then it considers the ones digit for each value. The rst value is removed and placed in the digit bin corresponding to the ones digit. For example, 534 is placed in digit bin 4 and 662 is placed in the digit bin 2. Once all the values in the main bin are placed in the corresponding digit bin for ones, the values are collected from bin 0 to bin 9 (in that order) and placed back in the main bin. The process continues with the tens digit, the hundreds, and so on. After the last digit is processed, the main bin contains the values in order. Use randint, found in random, to create random integers from 1 to 100000. Use a list comphrension to create a list of varying sizes (10, 100, 1000, 10000, etc.). To use indexing to access the digits rst convert the integer to a string. For this sort to work, all numbers must have the same number of digits. To zero pad integers with leading zeros, use the string method str.zfill(). Once main bin is sorted, convert the strings back to integers. I'm not sure how to start this, Any help is appreciated. Thank you.

    Read the article

  • What is difference between my atoi() calls?

    - by Lucas
    I have a big number stored in a string and try to extract a single digit. But what are the differences between those calls? #include <iostream> #include <string> int main(){ std::string bigNumber = "93485720394857230"; char tmp = bigNumber.at(5); int digit = atoi(&tmp); int digit2 = atoi(&bigNumber.at(5)) int digit3 = atoi(&bigNumber.at(12)); std::cout << "digit: " << digit << std::endl; std::cout << "digit2: " << digit2 << std::endl; std::cout << "digit3: " << digit3 << std::endl; } This will produce the following output. digit: 7 digit2: 2147483647 digit3: 57230 The first one is the desired result. The second one seems to me to be a random number, which I cannot find in the string. The third one is the end of the string, but not just a single digit as I expected, but up from the 12th index to the end of the string. Can somebody explain the different outputs to me? EDIT: Would this be an acceptable solution? char tmp[2] = {bigNumber.at(5), '\0'}; int digit = atoi(tmp); std::cout << "digit: " << digit << std::endl;

    Read the article

  • Is the last digit of a phone number random?

    - by sehugg
    I have a telephony app which has a prompt which requires user choice. I made the app select one of 10 different phone prompts based on the last digit of the caller's phone number. Then I measure whether the user responds to the prompt (accept) or decides to skip to the next step (reject). I thought this would work well enough as a random selection, but I think I may be wrong. What I'm finding is that the exact same prompt has a dramatically different response rate (25% vs 35%) for two different last digits. Now I'm curious why this is. Does anyone know how phone numbers are assigned and why the last digit would be significant?

    Read the article

  • How could I represent 1.625 by 0 or a 1 (binary digit)?

    - by pepito
    This is an excerpt from wikipedia about 'full rate' speech coding standard. Full Rate or FR or GSM-FR or GSM 06.10 was the first digital speech coding standard used in the GSM digital mobile phone system. The bit rate of the codec is 13 kbit/s, or 1.625 bits/audio sample. And this one is an excerpt from wikipedia about bit. In computing parlance, bit is the abbreviation for a single binary digit, represented by a 0 or a 1. How could I represent 1.625 by 0 or a 1? Actually, that's my lecturer's question that I could not answer. Some links to papers are more than welcome. Thanks in advance.

    Read the article

  • How would I find all sets of N single-digit, non-repeating numbers that add up to a given sum in PHP

    - by TerranRich
    Let's say I want to find all sets of 5 single-digit, non-repeating numbers that add up to 30... I'd end up with [9,8,7,5,1], [9,8,7,4,2], [9,8,6,4,3], [9,8,6,5,2], [9,7,6,5,3], and [8,7,6,5,4]. Each of those sets contains 5 non-repeating digits that add up to 30, the given sum. Any help would be greatly appreciated. Even just a starting point for me to use would be awesome. I came up with one method, which seems like a long way of going about it: get all unique 5-digit numbers (12345, 12346, 12347, etc.), add up the digits, and see if it equals the given sum (e.g. 30). If it does, add it to the list of possible matching sets. I'm doing this for a personal project, which will help me in solving Kakuro puzzles without actually solving the whole thing at once. Yeah, it may be cheating, but it's... it's not THAT bad... :P

    Read the article

  • How to create a Turing machine that takes a single digit decimal number from 0 - 9 and output the cu

    - by Julian
    I'm working on a project for a Turning machine but having problems conceptualizing the steps. f(x) = x^3, where x is a single digit between 0 - 9 inclusive. Based on my understanding I am to convert the number to binary but how do I find the cube of a number in binary. Also, how do I write the cube on the tape. So far I'm thinking I should create a state diagram that accepts the binary versions of 0-9 but what next?

    Read the article

  • What products support 3-digit region subtags, e.g., es-419 for Latin-American Spanish?

    - by Ektron Doug D
    What products support 3-digit region subtags, e.g., es-419 for Latin-American Spanish? Are web browsers, translation tools and translators familiar with these numeric codes in addition to the more common "es" or "es-ES"? I've already visited the following pages: W3C Choosing a Language Tag W3C Language tags in HTML and XML RFC 5646 Tags for Identifying Languages Microsoft National Language Support (NLS) API Reference

    Read the article

  • Most concise way to convert from date format: yyyy[3 digit day of year] to SQL datetime

    - by Seth Reno
    I'm working with an existing database where all dates are stored as integers in the following format: yyyy[3 digit day of year]. For example: 2010-01-01 == 2010001 2010-12-31 == 2010356 I'm using the following SQL to convert to a datetime: DATEADD(d, CAST(SUBSTRING( CAST(NEW_BIZ_OBS_DATE AS VARCHAR), 5, LEN(NEW_BIZ_OBS_DATE) - 4 ) AS INT) - 1, CAST('1/1/' + SUBSTRING(CAST(NEW_BIZ_OBS_DATE AS VARCHAR),1,4) AS DATETIME)) Does anyone have a more concise way to do this?

    Read the article

  • Is there a work around for invalid octal digit in an array?

    - by sircrisp
    I'm trying to create an array which will hold the hours in a day so I can loop through it for a clock. I have: int hourArray[24] = {12, 01, 02, 03, 04, 05, 06, 07, 08, 09, 10, 11, 12, 01, 02, 03, 04, 05, 06, 07, 08, 09, 10, 11}; I am getting the error on the following numbers in order 08, 09, 08, 09. It tells me: Error: invalid octal digit I've never run into this before and I'm wondering if there is any way around it?

    Read the article

< Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >