random

问题 I am attempting to make a fast password generator using multithreading with OpenMP integrated into Visual Studio 2010. Let's say I have this basic string generator that randomly pulls Chars from a string. srand(time(0)); for (i = 0; i < length; ++i) { s=pwArr[rand()%(pwArr.size()-1)]; pw+=s; } return pw; Now, the basic idea is to enable multithreading with OpenMP to enable really fast random char lookup, like so: srand(time(0)); #pragma omp parallel for for (i = 0; i < length; ++i) { s=pwArr

问题 Closed. This question is not reproducible or was caused by typos. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 1 year ago . Improve this question I try to figure out how dose the sample function work when I try to random select 10 samples in each group from the data frame. I have a data frame with 5 columns and 7000 rows. I split the dataset into around 200 groups. Then I want to random select 10 samples

问题 I have a bit weird requirement where I need to generate Random numbers of the length that is given by user. User can give Minimum Length and the Maximum Length and I need to generate the random numbers which consist of the character length between this range. For example if the Minimum Length is 6 and Maximum Length is 10 then I need to generate the random numbers whose number of characters has to be between the range 6 and 10 . For this example following can be the random generators: 123456,

问题 I'm trying to make a simple life simulator, and I need the "cells" to move almost randomly (with a few rules) across the screen. But the problem is, after a while they tend to bunch up in the upper-left corner of the screen. I tried to change a lot of things, like completely skipping the rules and making them move completely randomly, but they still bunch up. Is there some obvious problem in my code? Or should I be doing the movement completely differently? The code with irrelevant parts cut

问题 I'm trying to make a simple life simulator, and I need the "cells" to move almost randomly (with a few rules) across the screen. But the problem is, after a while they tend to bunch up in the upper-left corner of the screen. I tried to change a lot of things, like completely skipping the rules and making them move completely randomly, but they still bunch up. Is there some obvious problem in my code? Or should I be doing the movement completely differently? The code with irrelevant parts cut

问题 import java.util.ArrayList; import java.util.Random; public class College { // instance variables - replace the example below with your own private ArrayList<Student> students; public College() { // initialise instance variables ArrayList<Student> students = new ArrayList<Student>(); students.add("Student 1"); students.add("Student 2"); students.add("Student 3"); } } basically it highlights the .add showing the error message "java.lang.IllegalArgumentException: bound must be positive", I don

问题 import java.util.ArrayList; import java.util.Random; public class College { // instance variables - replace the example below with your own private ArrayList<Student> students; public College() { // initialise instance variables ArrayList<Student> students = new ArrayList<Student>(); students.add("Student 1"); students.add("Student 2"); students.add("Student 3"); } } basically it highlights the .add showing the error message "java.lang.IllegalArgumentException: bound must be positive", I don

问题 I usually generate random stuff in the following manner: Random random = new Random(DateTime.Now.Millisecond); for (int i = 0; i < 100; i++) { Console.WriteLine(random.Next(0, 100)); } I was wondering whether there is a difference if I put the Random instantiation within the loop: for (int i = 0; i < 100; i++) { Random random = new Random(DateTime.Now.Millisecond); Console.WriteLine(random.Next(0, 100)); } Which is more random or they are the same? 回答1: The first (i.e. outside the loop) is

问题 In javascript how do I randomly generate a number between -0.5 and 0.5? The following only seems to give positive numbers, and no negative numbers. Math.random(-0.15, 0.15) 回答1: Quoting MDN on Math.random, The Math.random() function returns a floating-point, pseudo-random number in the range [0, 1) that is, from 0 (inclusive) up to but not including 1 (exclusive) So, generate random numbers between 0 and 1 and subtract 0.5 from it. Math.random() - 0.5 Note: Math.random() doesn't expect any

问题 I want to echo random lines by PHP from file sitemap.txt that provide as: link1 link2 link3 link4 ... link10000 I have tried using this function: $lines = file("sitemap.txt"); $data[link] = $lines[array_rand($lines)]; But this $data[link] will echo output 1 random value only such as link1 or link10000 However, I need to echo 100 random values from sitemap.txt How can I optimize this function? Thanks 回答1: $lines = file("sitemap.txt"); $data = array_rand($lines, 100); foreach($data as $value) {