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Time complexity of Sieve of Eratosthenes algorithm
...oose upper-bound is n(1+1/2+1/3+1/4+1/5+1/6+…1/n) (sum of reciprocals of all numbers up to n), which is O(n log n): see Harmonic number. A more proper upper-bound is n(1/2 + 1/3 + 1/5 + 1/7 + …), that is sum of reciprocals of primes up to n, which is O(n log log n). (See here or here.)
The "find...
What is the difference between pull and clone in git?
...
They're basically the same, except clone will setup additional remote tracking branches, not just master. Check out the man page:
Clones a repository into a newly created directory, creates remote-tracking branches for each branch in ...
What is the Scala annotation to ensure a tail recursive function is optimized?
...e to Scala version 2.8.0.RC5 (Java HotSpot(TM) 64-Bit Server VM, Java 1.6.0_18).
Type in expressions to have them evaluated.
Type :help for more information.
scala> import scala.annotation.tailrec
import scala.annotation.tailrec
scala> class Tails {
| @tailrec def boom(x: Int): Int = {
...
How can I convert a string to a number in Perl?
...
You don't need to convert it at all:
% perl -e 'print "5.45" + 0.1;'
5.55
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How to trigger a file download when clicking an HTML button or JavaScript
...Edge) and it is not supported in Safari. In 2012 when the answer was originally posted it wasn't supported in any major browser.
– Cfreak
Jul 7 '16 at 3:40
2
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Vibrate and Sound defaults on notification
...gb format, like 0xffffffff, instead of Color.White, because there's is a small chance of user device use Color(RGB) for a ARGB param and you will get the wrong color. This Happened with me.
– Beto Caldas
Oct 24 '14 at 19:47
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Handling optional parameters in javascript
... second argument is a function or not:
function getData (id, parameters, callback) {
if (arguments.length == 2) { // if only two arguments were supplied
if (Object.prototype.toString.call(parameters) == "[object Function]") {
callback = parameters;
}
}
//...
}
You can also us...
How to get UILabel to respond to tap?
...= UITapGestureRecognizer(target: self, action: #selector(self.actionTapped(_:)))
tempLabel?.isUserInteractionEnabled = true
tempLabel?.addGestureRecognizer(tapAction)
Action receiver
func actionTapped(_ sender: UITapGestureRecognizer) {
// code here
}
Swift 4.0
Initialize the gesture...
What difference is there between WebClient and HTTPWebRequest classes in .NET?
...FtpWebRequest, depend on your request. Below is an example:
Example:
var _request = (HttpWebRequest)WebRequest.Create("http://stackverflow.com");
var _response = (HttpWebResponse)_request.GetResponse();
WebClient
System.Object
System.MarshalByRefObject
System.ComponentModel....
Uploading images using Node.js, Express, and Mongoose
...b.
// Expose modules in ./support for demo purposes
require.paths.unshift(__dirname + '/../../support');
/**
* Module dependencies.
*/
var express = require('../../lib/express')
, form = require('connect-form');
var app = express.createServer(
// connect-form (http://github.com/visionmedia...