Today I had the privilege of a job interview with one of the leading companies in the online streaming music space. I’d like to think the interview went well, although I was incredibly nervous and my brain decided it was going to operate in a way that suggested it was wading through treacle; but I digress. During the interview I was asked an algorithmic question and I have to admit I was initially quite flummoxed. This post is about that question. Continue reading “Set union problem”
This article is going to cover a typical interview test question, which asks you to find the missing number in an array. The array is N elements in size and contains all the numbers 1 to N. The numbers can be in any order but will never repeat. One of the numbers is missing and your task is to find the missing number as efficiently as possible. There are a number of different ways we could tackle this problem, which we’re going to explore. The focus of this article isn’t so much about how to solve this problem and more about the (in)efficiency of different algorithms we might use.
Virtual functions and default parameter arguments are a staple of all C++ programmers, but you might get more than you bargained for if you decide to mix and match them. Try this little quiz and see if your coders intuition is correct.
Templates are a hugely powerful feature of C++. They allow you to do so many different and cool things. Unfortunately, templates do have a bit of a reputation for having rather nasty syntax and for the most part this reputation is quite well deserved. This little quiz shows an example of some template syntax that you’ll only rarely come across but if you don’t know about it you could literally be left scratching your head in disbelieve, convinced you’ve uncovered a compiler bug.
Linked lists are an interviewers favourite subject matter. Whilst they are pretty easy to understand, at least in principle, they do require a little bit of brain warping to get your head around what’s going on under the hood. Of the common questions about linked lists I’ve come across, this quiz tackles the most common: how to reverse a linked list.
Included as part of the C++ Standard Template Library (STL) is a collection of generic containers. Each of these containers serves a different purpose and has different pros and cons. It is often difficult to decide which container to use and when to use it.
This article is a discussion on smart pointers, what they are and why they are important to C++ programmers. Following the primary discussion I present a simple implementation of a reference counted smart pointer and show a simple example of using it. Although this article does not go into detail about how to develop a reference counted smart pointer the example code at the end is very well commented and that should be enough to aid understanding.
Sometimes, just because you can do something doesn’t mean you should. Unfortunately, the C++ Standards Council missed that memo when they ratified the exception specifiers. To find out why, try this little quiz.
Need to store objects in an STL container? Need polymorphic behaviour meaning you’ll need to store pointers to a base class? Want to use a smart pointer to avoid memory leaks? Planning on using auto_ptr because it’s available as part of C++? Before you go any further, try this little quiz.
Ubiquitous use of smart pointers can prevent memory leaks and make for much easier to read and understand code. Unfortunately, as with most things C++, there are some caveats you need to be aware of otherwise your attempts to write robust code could very well come back to bite you. This little quiz shows how careless misuse of auto_ptr could open up a big can of worms.