Oren Dobzinski orend

GROKKING NOTES

I liked the way Grokking the coding interview organized problems into learnable patterns. However, the course is expensive and the majority of the time the problems are copy-pasted from leetcode. As the explanations on leetcode are usually just as good, the course really boils down to being a glorified curated list of leetcode problems.

So below I made a list of leetcode problems that are as close to grokking problems as possible.

Pattern: Sliding Window

Clojure on Raspberry Pi with OS X

"Clojure running on Raspberry Pi" sounded so cool that I just had to give it a try.

Install JDK

Download ARM JDK from Oracle and instlal on Raspberry Pi
Change visudo to contain the following

Let me explain what we're trying to do, which may be crazy. But if it's not crazy, perhaps someone can tell us how to use AMQP to do it.

We have a Rails app that talks to a growing number of backend Clojure services.

It could talk to them via HTTP, but many of the messages don't need to be synchronous. They're "fire and forget". Hence AMQP.

For the synchronous messages, we observed two things:

Serializing and deserializing HTTP is surprisingly annoying, especially given Rails conventions.
Most of the time when we send a message that updates a resource, we don't need a synchronous acknowledgement right away. We only need to know that the update has happened at some point before we next read the resource.

The Learning Haskell guide has been moved to a git repo to enable outside contribution

Find it here: https://github.com/bitemyapp/learnhaskell

Description

This simple script will take a picture of a whiteboard and use parts of the ImageMagick library with sane defaults to clean it up tremendously.

The script is here:

#!/bin/bash
convert "$1" -morphology Convolve DoG:15,100,0 -negate -normalize -blur 0x1 -channel RBG -level 60%,91%,0.1 "$2"

	require 'curses'

	module Seeder
	extend self
	def generate_matrix
	rand(40..200).times.map { [rand(24), rand(48)] }
	end
	end

	class Universe

	# config/routes.rb
	resources :documents do
	scope module: 'documents' do
	resources :versions do
	post :restore, on: :member
	end

	resource :lock
	end
	end

	http://www.infoq.com/presentations/Simple-Made-Easy
	http://www.infoq.com/presentations/integration-tests-scam
	http://blog.thecodewhisperer.com/2010/09/14/when-is-it-safe-to-introduce-test-doubles
	http://youtu.be/yTkzNHF6rMs
	http://pyvideo.org/video/1670/boundaries
	http://skillsmatter.com/podcast/ajax-ria/enumerators
	http://alistair.cockburn.us/Hexagonal+architecture
	http://c2.com/cgi/wiki?PortsAndAdaptersArchitecture
	http://www.confreaks.com/videos/977-goruco2012-hexagonal-rails
	http://www.confreaks.com/videos/1255-rockymtnruby2012-to-mock-or-not-to-mock

	describe MailingList do
	let(:notifications) { double('notifications') }
	let(:user) { User.new }

	it 'registers a new user' do
	expect(notifications).to receive(:call).with(user, 'list_name')

	mailing_list = MailingList.new('list_name', notifications)
	mailing_list.add(user)

	git for-each-ref --sort='-authordate:relative' --format='%(color:red)%(objectname:short) %(color:white)- %(color:yellow)(%(refname:short)) %(color:white)%(subject) %(color:green)(%(authordate:relative)) %(color:bold blue)<%(authorname)>' refs/heads \| more -R`

	# Or in `.gitconfig / [alias]`,
	rec = !git for-each-ref --sort='-authordate:relative' --format='%(color:red)%(objectname:short) %(color:white)- %(color:yellow)(%(refname:short)) %(color:white)%(subject) %(color:green)(%(authordate:relative)) %(color:bold blue)<%(authorname)>' refs/heads \| more -R