Swift: fix invalid url

Some urls contain special characters or contain arabic words and when you parse this url on swift you will get "Invalid url request" error.

to resolve this problem it very easy but i take long time with searching on google about it after if find the solution :

feed?.link.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)
let url = URL(string: (feed?.link)!)

Good Luck :)

To add new keyboard layout i3wm

To add secandary layout for i3wm it's just simple like like this to add in config file

~/.config/i3/config :
  

exec setxkbmap -layout us,ar -option grp:alt_shift_toggle

This comman is adding arabic as second layout and use same windows switch keys "ALT+SHIFT".

and this comman it's work on command line also but without exec .



Have fun :D

Which algorithms/data structures should I "recognize" and know by name?

This quote from 

https://softwareengineering.stackexchange.com

Which algorithms/data structures should I "recognize" and know by name? 

An objective response:

While my initial response to this question was based on my empirical experience as a soon-to-graduate CS student and my projected opinion of the type of people I wanted to work with in the CS field. There is actually an objective (with respect to the subjective opinions of the ACM SIGCSE and IEEE computing societies) answer. Every 10 years the ACM and the IEEEbodies cooperate on a joint publication that details suggestions for undergraduate computer science curriculum based on professional knowledge of the state of the computing industry. More information can be found at cs2013.org. The committee publishes a final report listing their curriculum recommendation.

That said, I still think my list is pretty good.

Original answer below.

What Should I Know?

Minimum

I think an adept programmer should have at least undergraduate level knowledge in Computer Science. Sure, you can be effective at many jobs with only a small subset of Computer Science because of the rock solid community CS sits upon, and the narrowed focus of most professional positions. Also, many people will further specialize after undergraduate study. However, I do not think either are an excuse to not be privy of foundational CS knowledge.

To answer the title question, here is what an undergraduate CS student (the foundation for an adept programmer) should know upon graduation:

Data Structures

Machine Data Representation

Ones, Two's Complement, and Related Arithmetic

Words, Pointers, Floating Point

Bit Access, Shifting, and Manipulation

Linked Lists

Hash Tables (maps or dictionaries)

Arrays

Trees

Stacks

Queues

Graphs

Databases

Algorithms

Sorting:

Bubble Sort (to know why it's bad)

Insertion Sort

Merge Sort

Quick Sort

Radix style sorts, Counting Sort and Bucket Sort

Heap Sort

Bogo and Quantum Sort (=

Searching:

Linear Search

Binary Search

Depth First Search

Breadth First Search

String Manipulation

Iteration

Tree Traversal

List Traversal

Hashing Functions

Concrete implementation of a Hash Table, Tree, List, Stack, Queue, Array, and Set or Collection

Scheduling Algorithms

File System Traversal and Manipulation (on the inode or equivalent level).

Design Patterns

Modularization

Factory

Builder

Singleton

Adapter

Decorator

Flyweight

Observer

Iterator

State [Machine]

Model View Controller

Threading and Parallel Programming Patterns

Paradigms

Imperative

Object Oriented

Functional

Declarative

Static and Dynamic Programming

Data Markup

Complexity Theory

Complexity Spaces

Computability

Regular, Context Free, and Universal Turing Machine complete Languages

Regular Expressions

Counting and Basic Combinatorics

Beyond

To get into what you're asking about later in your question, if you are familiar with the above, you should be easily able to identify the appropriate pattern, algorithm, and data structure for a given scenario. However, you should recognize that there is often no best solution. Sometimes you may be required to pick the lesser of two evils or even simply choose between two equally viable solutions. Because of this, you need the general knowledge to be able to defend your choice against your peers.

Here are some tips for algorithms and data structures:

Binary Search can only (and should) be used on sorted data.

Radix style sorts are awesome, but only when you have finite classes of things being sorted.

Trees are good for almost anything as are Hash Tables. The functionality of a Hash Table can be extrapolated and used to solve many problems at the cost of efficiency.

Arrays can be used to back most higher level data structures. Sometimes a "data structure" is no more than some clever math for accessing locations in an array.

The choice of language can be the difference between pulling your hair out over, or sailing through, a problem.

The ASCII table and a 128 element array form an implicit hash table (=

Regular expressions can solve a lot of problems, but they can't be used to parse HTML.

Sometimes the data structure is just as important as the algorithm.

Some of the above might seem like no brainers, and some may seem vague. If you want me to go into more detail, I can. But, my hope is when encountered with a more concrete question such as, "Design a function that counts the number of occurrences of every character in a String", you look to the tip about the ASCII table and 128 element arrays forming neat implicit hash tables for the answer.

Based off these ideas, I will propose an answer the locker problem outlined in your question.

Answer to the problem posed in your question.

This may not be the best answer to your question, but I think it's an interesting one that doesn't require anything too complex. And it will certainly beat the time complexity of using a queue, or stack which require linear time to determine whether a locker is free or not.

You have 0-999 lockers. Now, because you have a fixed number of lockers, you can easily conceive a hashing function with no collisions on the range 0-999. This function is simply h(x) = x mod 1000. Now, [conceptually] construct a hash table with integer keys and the contents of a 1000 element char array as your values. If a customer wants to reserve locker 78 for use, simply put 78 into the hash function (returning 78), and then add that number to the base pointer of the array -- storing a true value at the location pointed to by the offset value. Similarly, if you need to check whether 78 is in use, simply read the value stored at that location and check against true.

This solution operates in constant time for lookups and storage as opposed to a log(n) time storage and lookup in the case of a priority queue backed by a binary tree. The description is intentionally verbose so you can see the higher concepts being boiled down into an efficient algorithm.

Now, you might ask, what if I need to know all of the available lockers, wouldn't a priority queue be better? If there are k available lockers in the priority queue, iterating over all of them will take k steps. Further, depending on your priority queue implementation, you might have to rebuild your priority queue as you look at it all.. which would take k*log(k) : (k < 1000) steps. In the array solution, you only have to iterate of a 1000 element array and check which ones are open. You can also add an available or used list to the implementation to check in k time only.

Vaping Batteries Explained: What to buy? What is the Best Battery?

How to install Hearthstone on Linux

 

How to install Hearthstone on Linux
using "Wine" and "Play on Linux"

1. Get "Play on Linux" from http://www.playonlinux.com/en/download.html

2. Launch "Play on Linux" you should be asked to install any Wine version, you should install  version "1.7.3"

3. Click "Install" and then check "Testing"

4. Search for "World of Warcraft" and wait till you see it in the list, mostly it should already be there.

5. Click "Install" then tell the wizard to use Wine 1.7.3 leave the remaining settings at default.

6. When your asked to select the install File for "World of Warcraft" just cancel the Wizard.

7. Click Install again, then select "install non-listed program".

8. On the second page of the wizard select "Edit or update an existing application", on the next window check "Show virtual drives" and select "WorldOfWarcraft".

9. Check "Configure Wine" and select the tab "Libraries" tab.

10.  type "dbghelp" in the "New override for library" field then click "Add"

11. click "Edit ..." and select "disabled", confirm this with "Ok"

12. On the next screen select "Choose another File"

13. The remaining installation is like the installation of every other Wine Software.

14. After launching Hearthstone first time you probably want to change the settings to run Hearthstone in windowed mode, otherwise you'll probably get massive graphics stuttering.

2013-10-26

2 photos

 

reffrence: Markus Weller

Get Object from selected Element JTable in Netbeans

To get Object or Entity from JTable in Netbeans

System.out.println(list1.get(Table.convertRowIndexToModel(Table.getSelectedRow())));

Install silverlight in linux

This post taken from webupd8.org

I've tested Pipelight with Netflix, under Chrome (Ubuntu 13.10) and I can confirm it works (and the playback was smooth!), as you can see in the screenshots in this article. Update: I've also tested it with Firefox and it works, but sometimes the browser freezes, something which doesn't happen with Chrome so I recommend using Chrome / Chromium with Pipelight.

Install Pipelight in Ubuntu

Before proceeding, it's strongly recommended to close your web browser. Without doing this, the plugin may fail to install or crash the browser (you can copy the instructions below to a text editor).

1. If you've installed the old Pipelight version, remove it before proceeding:

sudo apt-get remove pipelight

To add the Pipelight stable and Compholio PPAs and install Pipelight in Ubuntu, use the following commands:

sudo apt-add-repository ppa:pipelight/stable
sudo apt-get update
sudo apt-get install pipelight-multi

Then, you can install the Silverlight plugin using the following command:
- system-wide:

sudo pipelight-plugin --enable silverlight

- for your user only:

pipelight-plugin --enable silverlight

By default, this will install Silverlight 5.1, but you can install a different version, for instane 5.0, by using this command instead (don't use "sudo" if you don't want to install it system-wide):

sudo pipelight-plugin --disable silverlight --enable silverlight5.0

Once installed, start your browser and try THIS test Silverlight applet. If it doesn't work, check if Silverlight is available in your browser plugin list (e.g.: you can type "about:plugins" in the address bar).