How to Find Multiple Missing Integers in Given Array of Numbers with Duplicates in Java?

It's been a long time since I have discussed any coding or algorithm interview questions, so I thought to revisit one of the most popular array based coding problem of finding missing numbers in a given array of integers. You might have heard or seen this problem before on your programming job interviews and you might already know how to solve this problem. But, there are a lot of different versions of this problem with increasing difficulty levels which interviewers normally use to confuse candidate and further test their ability to adapt to frequent changes. In the past I have demonstrated how to find the missing number in a sorted array as well on the unsorted integer array in Java using BitSet (see here), but, with just one missing number and without any duplicates, which kinda make those problems a bit easier.

Top 5 Courses to Learn Flutter in 2019 - Best of Lot

If you are like me who think Flutter is the future of mobile development and looking for some awesome online courses to learn Flutter then you have come to the right place. In this article, I am going to share some of the best online courses to learn Flutter in 2019 from Udemy, Pluralsight, and Coursera, but before going into that, let's see what is Flutter and why everyone is so excited about it. Well, in general, whenever something comes from Google it makes a lot of developers excited like Angular, Dart, and now Flutter. I have got my hand dirty in both Android and iOS using Java and Objective-C in the past but after working for some time, I decided to move on.

Is "Java Concurrency in Practice" Still Valid in the Era of Java 8 and 13?

One of my reader Shobhit asked this question on my blog post about 12 must-reads advanced Java books for intermediate programmers - part1. I really like the question and thought that many Java programmers might have the same doubt whenever someone recommends them to read Java Concurrency in Practice. When this book came first in 2006, Java world was still not sure of about new concurrency changes made in Java 1.5, I think the first big attempt to improve Java's built-in support for multi-threading and concurrency. Many Java programmers were even not aware of new tools introduced in the API e.g. CountDownLatch, CyclicBarrier, ConcurrentHashMap and much more. The book offered them the seamless introduction of those tools and how they can use them to write high-performance concurrent Java applications.

The 2019 DevOps Developer RoadMap - Your Guide to become DevOps Engineer

DevOps is really hot at the moment and most of my friends, colleagues and senior developers I know are working hard to become a DevOps engineer and project themselves as DevOps champion in their organization. While I truly understand the benefit of DevOps, which is directly linked to improved software development and deployment, from my limited experience I can say that it's not an easy job. It's very difficult to choose the right path in mind of so many tools and practices. Many of my readers also ask me this question is how to become a DevOps engineer, which tools should I learn? which practices should I follow? does learning Maven and Jenkins must for a DevOps guy? how about Docker and Kubernetes? Does infrastructure automation part of DevOps? should I learn Chef, Puppet, or Ansible are just some of those questions which keep coming to me.

Teachable or Udemy? Which Platform is best for Creating Online Courses?

I have been researching a lot about how to create a successful online course since last year. I have yet to launch my course but I have also started mentoring many of readers about creating online courses and why they should create it. Why I am doing this? because I believe together we can learn better and succeed. If I have a group of passionate developers who like to teach online, there is a better chance of creating a successful online course. Anyway, one of the common questions which keeps popping up is which platform is better for beginners, Teachable, or Udemy? Which has better support for creating and selling online courses? If you also have similar doubt, then you have come to the right place. In this article, I'll share some of my understanding and insight about Teachable and Udemy, two of the most popular online course platform which will help you to make a decision.

Top 5 MongoDB Online Training Courses for Programmers and Web Developers

MongoDB is one of the leading NoSQL databases and it was on my radar for a long time but I never get a chance to learn or work on it, but Recently I got an opportunity to use MongoDB for one of our projects and I learned a lot on the way. In this article, I will introduce MongoDB and how to learn MongoDB so that you can use it in your project. In this article, I will share some of the online courses which I have taken to understand everything up to the basic CRUD (Create, Retrieve, Update, Delete) operations on MongoDB. I have also read a couple of books and followed some tutorials but these courses were my main source to learn Mongo DB.