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What are the differences between NP, NP-Complete and NP-Hard?
... the technical definitions require quite some time to understand. First of all, let's remember a preliminary needed concept to understand those definitions.
Decision problem: A problem with a yes or no answer.
Now, let us define those complexity classes.
P
P is a complexity class that repres...
Injecting a mock into an AngularJS service
...e.
If you have the following service with a dependency that has a method called getSomething:
angular.module('myModule', [])
.factory('myService', function (myDependency) {
return {
useDependency: function () {
return myDependency.getSomething();
}...
How can I use UUIDs in SQLAlchemy?
... dialect supports UUID columns. This is easy (and the question is specifically postgres) -- I don't understand why the other answers are all so complicated.
Here is an example:
from sqlalchemy.dialects.postgresql import UUID
from flask_sqlalchemy import SQLAlchemy
import uuid
db = SQLAlchemy()
...
Is it possible to create static classes in PHP (like in C#)?
...
You can have static classes in PHP but they don't call the constructor automatically (if you try and call self::__construct() you'll get an error).
Therefore you'd have to create an initialize() function and call it in each method:
<?php
class Hello
{
private static...
Reference - What does this error mean in PHP?
...m. (Note: You might have multiple blocks if you had code that was automatically constructed)
Also make sure you don't have any Byte Order Marks in your code, for example when the encoding of the script is UTF-8 with BOM.
Related Questions:
Headers already sent by PHP
All PHP "Headers already sen...
What is context in _.each(list, iterator, [context])?
...
The context lets you provide arguments at call-time, allowing easy customization of generic pre-built helper functions.
some examples:
// stock footage:
function addTo(x){ "use strict"; return x + this; }
function pluck(x){ "use strict"; return x[this]; }
function l...
Using the Underscore module with Node.js
...rom Underscore, it overwrites the _ object with the result of my function call. Anyone know what's going on? For example, here is a session from the node.js REPL:
...
Python threading.timer - repeat function every 'n' seconds
... not self.stopped.wait(0.5):
print("my thread")
# call a function
In the code that started the timer, you can then set the stopped event to stop the timer.
stopFlag = Event()
thread = MyThread(stopFlag)
thread.start()
# this will stop the timer
stopFlag.set()
...
No generic implementation of OrderedDictionary?
...s methods for sorting the way that List<T> does since this is essentially a hybrid IList and IDictionary. I've included my implementation here for posterity.
Here's the interface. Notice that it includes System.Collections.Specialized.IOrderedDictionary, which is the non-generic version of t...
The required anti-forgery form field “__RequestVerificationToken” is not present Error in user Regis
...rs typing http were getting this error, putting in a rewrite rule to force all to https://{HTTP_HOST}/{R:1} fixed it
– user1069816
Mar 24 '16 at 15:30
...