April Marathon and Live Broadcast

CodeFights coding tournament marathon

You might not know that every month we run a huge coding tournament. We call them Marathons, but unlike a running marathon, they only last one hour. (And your legs won’t hurt tomorrow!) Each Marathon consists of 10 questions that have been specially created by our team of Content Engineers. They’re fun, they’re tricky, and they’ll get your brain in gear! And if you’ve never participated in a competitive coding event before, this is the perfect introduction. Participate If you want

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CodeFights Solves It: findSubstrings

trie data structure Uber technical interview question

The Interview Practice Task of the Week was findSubstrings. This is an Uber interview question, and their technical interviews are notoriously lengthy and difficult. And the solution implements tries, a data structure that you’ll see a lot in interview questions. It’s a double whammy! You know the drill by now: If you haven’t solved this challenge yet, hop on over to CodeFights and do it! Then come back here and we’ll walk through solving it together. We’ll start with a

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San Francisco Live Tournament Recap

Tigran Sloyan at live CodeFights coding tournament

On Saturday, April 22, CodeFighters from all over the Bay Area packed into the new CodeFights office and made history at the first-ever live San Francisco tournament. Some long-time CodeFighters already knew each other, but for many it was their first time meeting up with other users in real life. The room rang with friendly chatter… right up until the tournament started, and then everyone got down to business. The packed room was nearly silent during the hour-long tournament. CodeFighter xiaowuc1 pulled

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CodeFights Solves It: isTreeSymmetric

tree coding challenge interview question

The most recent Interview Practice Challenge of the Week was isTreeSymmetric. This interview question from LinkedIn and Microsoft is checking to see how comfortable you are with the tree data structure. Trees have a wide variety of applications, so your interviewer is going to make sure that you know your stuff! Have you solved it yet? If not, head over to CodeFights and give it a shot. Once you have a solution, come back here and I’ll walk you through

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Interview Practice Task of the Week

technical interviews practice challenge of the week

Have you been using our Interview Practice module to prepare for technical interviews? If not, you definitely should be! Interview Practice has over 100 questions that get asked by top companies during real interviews. (Which companies, you ask? Oh, you know. Just lil’ companies like Apple, Facebook, Google, Microsoft, Twitter, and more.) The topics are ones that you’ll definitely encounter – coding patterns, algorithms, and data structures. You need to be strong these topics in order to do well in technical interviews,

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CodeFights Explainer: Trees

data structures trees

Trees. They’re considered to be a computer science basic, but if it’s been a while since you’ve dealt with them – or if you’ve never encountered them before at all – they can be daunting. But tree questions are extremely common in technical interviews, so they’ll come up while you’re finding a job. And then on the job, they’re a wildly useful data structure. So let’s get you up to speed on trees! A tree is a data structure that

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Live Tournament in San Francisco

Special event San Francisco Coding Tournament

Bay Area CodeFighters, come join us on Saturday, April 22, for a special event: We’re breaking in our new San Francisco office by hosting a special live one-hour tournament! Meet the CodeFights team, hang out with other Bay Area coders, and compete for bragging rights, prizes, and CodeFights swag. The top three participants will all get $50 Amazon gift cards, and the first place winner will also get a special CodeFights gift box. Tournament Details 2:30 – Check in, hang out, eat snacks

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CodeFights Solves It, Interview Practice Edition: groupsOfAnagrams

Interview question: Find the groups of anagrams from an array.

This week’s featured Interview Practice challenge was groupsOfAnagrams. It’s a Twitter interview question, and they’re known for their difficult technical interviews! If you haven’t solved it yet, go ahead and do that first, then head back here and we’ll discuss how to get to a solution with a good runtime. …Done? Okay, let’s dig into this coding challenge! The technical interview challenge You are given a list of n words. Two words are grouped together if they are anagrams of

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Ace Your Phone Screen By Telling Your Story, Pt. 2

Ace your phone screen by telling your story

In Part 1 of this series, you learned how to craft a Story that will resonate with recruiters. Now we’ll talk about exactly how to tell the recruiter your Story during your phone screen. So you’ve prepared your Story and practiced it a few times. You’ve got your next phone screen scheduled. Now you just need to wow the recruiter! Be ready When it’s time for the phone screen, be ready at the agreed-upon time. The recruiter may call a few

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CodeFights Explainer: Prefix Sums

Prefix Sums

Prefix sums, or cumulative sums, allow us to quickly find the sum of any contiguous slice of an array. As a quick example, suppose you copy down some driving directions. They tell you to drive down Penny Lane for 3 miles, then make a left onto Abbey Road, which we travel down for 5 miles before continuing on Lake Shore Drive for 4 miles, and so on. We convert these directions into the number of miles driven on each road.

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