Tutorial by Examples: u

Longest Common Subsequence Explanation

One of the most important implementations of Dynamic Programming is finding out the Longest Common Subsequence. Let's define some of the basic terminologies first. Subsequence: A subsequence is a sequence that can be derived from another sequence by deleting some elements without changing the orde...

algorithm • Longest Common Subsequence

Capture groups

extern crate regex; use regex::Regex; fn main() { let rg = Regex::new(r"was (\d+)").unwrap(); // Regex::captures returns Option<Captures>, // first element is the full match and others // are capture groups match rg.captures("The year was 2016")...

Rust • Regex

UITextField - Restrict textfield to certain characters

If you want to perform a user input validation of your textfield use the following code snippet: // MARK: - UITextFieldDelegate let allowedCharacters = CharacterSet(charactersIn:"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvxyz").inverted func textField(_ textField:...

iOS • UITextField Delegate

Minify HTML using gulp-htmlmin

First, Install gulp and gulp-htmlmin to project directory locally npm install --save-dev gulp gulp-htmlmin Then add the minify-html task to your gulpfile.js var gulp = require('gulp'); var htmlmin = require('gulp-htmlmin'); // Task to minify HTML gulp.task('minify-html', function() { retu...

gulp • Minifying HTML

Get the top most UIViewController

A common approach to get the top most UIViewController is to get the RootViewController of your active UIWindow. I wrote an extension for this: extension UIApplication { func topViewController(_ base: UIViewController? = UIApplication.shared.keyWindow?.rootViewController) -> UIViewController ...

iOS • App wide operations

Single Source Shortest Path Algorithm (Given there is a negative cycle in a graph)

Before reading this example, it is required to have a brief idea on edge-relaxation. You can learn it from here Bellman-Ford Algorithm is computes the shortest paths from a single source vertex to all of the other vertices in a weighted digraph. Even though it is slower than Dijkstra's Algorithm, i...

algorithm • Bellman–Ford Algorithm

Delete files using del

First, Install gulp and del to project directory locally npm install --save-dev gulp del Then add the clean task to your gulpfile.js var gulp = require('gulp'); var del = require('del'); gulp.task('default', function() { }); // Task to delete target build folder gulp.task('clean', func...

gulp • Delete Files Using Gulp

Simple Express logging of all request to STDOUT

Add the following code to your app.js file: var express = require('express') var morgan = require('morgan') var app = express() app.use(morgan('combined')) app.get('/', function (req, res) { res.send('hello, world!') }) Now when you access your website you will see in the console y...

express • Logging

Create custom Target

using NLog; using NLog.Config; using NLog.Targets; namespace MyNamespace { [Target("MyFirst")] public sealed class MyFirstTarget: TargetWithLayout //or inherit from Target { public MyFirstTarget() { //set defaults ...

nlog • Extending NLog

Create custom Layout Renderer

[LayoutRenderer("hello-world")] public class HelloWorldLayoutRenderer : LayoutRenderer { /// <summary> /// I'm option and not required or default /// </summary> public string Config1 { get; set; } /// <summary> /// I'm required option. ...

nlog • Extending NLog

Installation or Setup

This would be a basic setup in wich we will send all the log messages to the console and to a log file. Let's start with the libraries. Will use maven for that: <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-api</artifact...

log4j2 • Getting started with log4j2

Web Page Using Materializecss

Here is an example of a basic page using the Materialize CSS framework which incorporates the grid system and materialboxed. <!DOCTYPE html> <html> <head> <title>Materializecss Example webpage</title>  <link href="ht...

materializecss • Getting started with materializecss

Deref implementation for Option and wrapper structure

use std::ops::Deref; use std::fmt::Debug; #[derive(Debug)] struct RichOption<T>(Option<T>); // wrapper struct impl<T> Deref for RichOption<T> { type Target = Option<T>; // Our wrapper struct will coerce into Option fn deref(&self) -> &Option...

Rust • Auto-dereferencing

Solving a univariate inequality

>>> from sympy.solvers.inequalities import solve_univariate_inequality >>> from sympy import var >>> x=var('x') >>> solve_univariate_inequality(2*x**2-6>1,x,relational=False) (-oo, -sqrt(14)/2) U (sqrt(14)/2, oo) The relational=False parameter simply ind...

sympy • Solvers

Before Submit: Validate record before it is committed to database

For this example, we want to make sure that any Employee who is marked as a Project Resource also has an appropriate Labor Cost defined. // 1.0, Revealing Module pattern var myNamespace = myNamespace || {}; myNamespace.example = (function () { /** * User Event 1.0 example detailing...

netsuite • User Event: Before and After Submit events

After Submit: Determine whether a field was changed

After the record gets stored in the database, we want to inspect what was changed on the record. We'll do this inspection by comparing values between the old and new record instances. // 1.0, Revealing Module pattern var myNamespace = myNamespace || {}; myNamespace.example = (function () { ...

netsuite • User Event: Before and After Submit events

Modifying the UI form

// 1.0 // Revealing Module pattern, structures 1.0 similar to 2.0 var myNamespace = myNamespace || {}; myNamespace.example = (function () { /** @appliedtorecord employee */ var exports = {}; function beforeLoad(type, form, request) { showBonusEligibility(form); ...

netsuite • User Event: Before Load event

Restrict execution based on the action that triggered the User Event

// 1.0 // Utilize the type argument and raw Strings to filter your // execution by the action function beforeLoad(type, form, request) { // Don't do anything on APPROVE // Note that `type` is an Object, so we must use ==, not === if (type == "approve") { return...

netsuite • User Event: Before Load event

Restrict execution based on the context that triggered the User Event

In SuiteScript 1.0, we retrieve the current execution context using nlapiGetContext().getExecutionContext(), then we compare the result to the appropriate raw Strings. // 1.0 in Revealing Module pattern var myNamespace = myNamespace || {}; myNamespace.example = (function () { var exports =...

netsuite • User Event: Before Load event

Reading a String from Standard Input

The STDIN stream in Julia refers to standard input. This can represent either user input, for interactive command-line programs, or input from a file or pipeline that has been redirected into the program. The readline function, when not provided any arguments, will read data from STDIN until a newl...

Julia Language • Input