I thought this was going to be similar to matrix rotation but it’s shape is very different. You can go about this three ways (it’s personally hard for me to find one that’s clearly the most legible so maybe there’s value in showing all three strategies.).

This is one of those questions where you can immediately tell there are many “expensive” ways to do this.

This question seems very easy: find the longest common prefix between a set of words.

I used to be very afraid of a matrix question. I now view it as a bit of a gift, as it’s a highly visual format, and graphs and trees are a little harder to mentally parse. But the matrix structure has some tricks to it that it simply helps you to know. i.e. Matrix rotation is pretty difficult to write a raw algorithm for but does it help you know that rotation is the same as transposing and then inverting each row? I think that only helps if you know exactly what transposing is. Let’s start there.

So I recently got this one at a company I was ok not working at. The interview shows me 2 3 x 3 arrays with numbers 0-9, and a 3rd 3 x 3 array, this one numbered 4-12. The goal with this problem is when given the path of a king on a chessboard, is this a valid route where the king travels through each square on the board sequentially.

Here’s a quick one. We commonly do iterations that lead to character counts. This one is looking for a moment where the left side and the right side have the same character count. In my interview, I quickly setup a for loop with a while loop inside it that found the counts, however this is way to algorithmly complex O(n^2). Of course then the interviewer asks for a better answer and left I’m scambling to find a better answer. I’ll give you a clue in case you run into this, when the question wants you to compare one side of an array to another, that is a tell to try this with 2 for loops, one after the other. 2 non-nested for loops is O(2n) ~ which is the same as 0(n). When you do something that’s 0(n^2), there might be a way you can do this with unnested loops, or nLog(n), or maybe use sorting.

data structures and algorithms challenges, abbreviated ‘DSA’, is a common and sometimes frustrating litmus test for interviewing software engineers. I’m interested in blogging all my recent challenges to confirm my understanding and put the knowledge out there without a paywall or login. I am newer to using python for coding challenges, but I feel like while I’m still true to javascript, python works better for these toy challenges.

Merge Intervals

Find the median of two sorted arrays

This is one of those questions where you can overlook edgecases immediately if you opt for a purely linear approach. If it seems easy, in this case it’s like leetcode medium, maybe it’s actually harder. I’ve done this one and immediately gotten the first three test cases to pass, and then the zeroth case (string = ‘’) isn’t handled. That should actually clue you in to the face that you are probably missing other cases as well. In my case, I was missing the case of abcadef, i.e. I found abc, and restarted and found adef, missing bcadef. This is a signal to consider while looping through a sliding window approach, rather than a linear approach. Additionally you can probably get by with a dictionary in python but I think a set is the best way to document substring uniqueness.

I wanted to start off by saying succinctly and firmly that I believe using regular expressions are often more time complex, certainly less intuitive, and often only effective for niche situations when it comes to solving coding challenges and interview questions… however, I am still fascinated with it!

Tonight, I watched Cassandra’s talk on functional programming, and I got pretty excited about currying, composing, and piping functions. I wanted to live code some practical examples, as I must admit it took seeing this several times for me to really wrap my head around this topic and I hope this helps!

There are many obvious benefits to working your computer from the terminal. I’ve been experimenting with opening tabs and running chains of commands from the terminal. Here’s a command to do exactly this.

In my few weeks in Telegraph Academy, I’ve discovered I learn best from live coding and I want to bring some of that feel to my blog. Live coding is a programming practice centered on the use of improvising interactive programming, there are live websites with many free, live tutorials and others simply challenging them to build something in a short period of time.

One reason I find them valuable is unlike slides, contrived exercises or doing the problem on your own, the live-coder puts on a show and gives me a chance to see an idea take shape. It also gives me confidence knowing that a quote-enquote professional programmer also makes typos, forgets keywords, and needs a moment to look at documentation. Finally, live coding also helps me establish patterns to look for and makes practical and succinct examples.

For example, I have been struggling with the concept of call, apply, and bind and a live coding session in class went a long way towards demistifying it for me. Here’s an expanded look at it! Open your console and try this out:

The Command Key (⌘) & Shortcuts and Development tools.

New programmers seem afraid of regular expressions. I love these particular tools and wanted to offer a full primer from abc to ^M{0,4}(CM|CD|D?C{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})$ . Regular expressions are a very old computer science concept that uses patterns to match subsets of strings. They are language agnostic, and can be a tool that you use for matching and modifying urls and other strings within your applications and for solving interview questions in a quirky manner.

I’m very excited to get this blog up and running and write my first post! Today is an important day in our country, gay marriage was declared legal all over our country, by the U.S. supreme court. As someone with many LGBTQ friends and some family, I feel a deep connection and am proud that our country will allow any two kinds of people to receive the over 1,000 benefits that marriage bestows.