Google Foobar Error Compiling the Code Please Try Again Later

WALK-THROUGH

My Google Foobar journey

Level ane — getting the invitation.

FooBar Completion Screenshot ( image by writer: Pratick Roy )

Index

1. My Google FooBar Journey : Level one- Getting the Invitation. (This one)
2. My Google FooBar Journey: Level 2.1 — Lift Maintenance.

How it started

The twelvemonth was 2016–2017ish. I was a young computer scientific discipline college student, who badly wanted to be a programmer. I loved to code and build stuff, and I every bit hated doing MCQs (Multiple Selection Questions).

To me MCQs are an anathema to everything engineering should be . To do well in MCQs, y'all must memorize a k shortcut formulas, larn to apply tricks instead of applying concepts, and religiously avoid trying to respond the hard problems, all in an endeavour to respond every bit many easy problems in equally footling time as possible.

Now I was nonetheless in school, but to me logically information technology seemed that,

As an engineer, my job description is to take a sufficiently big, hard, and ambiguous problem, learn, unlearn and relearn concepts, in society to break information technology down into smaller simpler problems, giving information technology more and more than shape over fourth dimension, until I take a good clean solution to the core concept of the problem, and its many surrounding edge cases.

Looking back with hindsight, I deem my younger self to be spot on with this analysis.

Withal, all higher placement job interviews would invariably begin with MCQ rounds, so I think you can well gauge my paranoia of non making out of college with a job offering in hand.

And then one fine day, as I was petty away at some cake of lawmaking, I probably got some error, or needed to look upwards some syntax, and as I Googled, the browser contorted to show me this message

FooBar Invitation ( image by author: Pratick Roy )

Now, being someone who codes for fun, I wanted to play, just past the time the screen animations took place, I had already clicked on the first stack-overflow link. I fervently hit the back push button, but no luck.

I was distraught. I realised the gravity of the error I just committed. I knew from previous reddit thread reads, what this challenge was about. It was Google FooBar Challenge[1]. I had just got an invitation, and I managed to squander information technology.

Now, If you are unaware of what this claiming is all near, only put it is Google's invite only undercover hiring procedure. Once invited, yous get to solve coding challenges, and if y'all complete it, yous get a shot at a straight interview with Google. Moreover, the standard barriers of ridiculously strict fourth dimension limits and the disability to use the internet, that are the patent of most online coding challenges and interview processes do not apply. You lot are given copious amounts of time to read, empathize, research, tinker with and solve the problem.

If it isn't obvious already, this was only the sort of claiming I was pining for. And I had messed up my one chance at seizing it. Existence a stoic however, I managed to quickly get back up and express mirth nigh how big of a klutz I was.

And that was that, life went on as usual, so with a mix of luck and difficult work, I managed to crack an internship opportunity at Amazon, giving me six months to prove my mettle in a real world software development setting. Another shot at playing my kind of game.

I know there might exist a bit of survivorship bias talking hither, but Seneca had once said,

Luck is what happens when preparation meets opportunity.[2]

And this time I was prepared and didn't make any stupid mistakes. Since then, I take been an Amazonian, and super proud of it, and the memory of the challenge that got abroad slowly began to fade from memory.

How information technology ended

Then near a few months dorsum about 4 years since that fateful mis-click, as I was again stuck on some code, and was looking to leverage the wisdom of developers who have solved the problem before me, my browser over again contorted to show me a familiar message.

FooBar Invitation ( image past author: Pratick Roy )

And this time I didn't repeat the faux pas. This time around the stakes were lower, I didn't need the chore interview anymore, just I wanted the claiming. I said I wanted to play and I was in.

And that brings me to last weekend, when I submitted the code to the last question. The challenge that had once got abroad was finally complete.

And Now The Journey

Have y'all e'er taken a trip that you have been planning for a long time, building information technology upwards in your head, simply to be disappointed when in the end yous get there. This was not one of those journeys.

Nosotros are a species of storytellers, and fooBar makes you the protagonist in a story to infiltrate and dismantle Commander Lambda's evil system, where all y'all take are your wits well-nigh you lot to save your bunny comrades.

And along this journey, you lot will learn as you go. From Markov Chains, to Cellular automata, at that place are so many fascinating ideas and concepts that the challenge exposed me to.

If you get the invite, and you like to code and like a claiming I'll strongly recommend you take FooBar up on the offering.

One other point to annotation, if you are comfortable with python, it might brand a lot of sense to go with it, every bit the standard library will provide you lot lots of useful functions. I personally used Coffee, as I am more comfy with it, and frankly I am non a big fan of Python. Maybe anytime I'll write a mail on disfavor to python. If then I'll link it here.

This mail is now getting likewise big for my taste, so in the next few posts, I'll become through the challenges 1 by 1, highlighting the learnings and insights that I gleamed from this challenge.

But before signing off, allow's solve Level i, Question i.

Level one

Question 1 : Re-ID

There'due south some unrest in the minion ranks: minions with ID numbers like "1", "42", and other "adept" numbers have been lording it over the poor minions who are stuck with more slow IDs. To quell the unrest, Commander Lambda has tasked
you with reassigning everyone new random IDs based on a Completely Foolproof Scheme.

Commander Lambda has concatenated the prime numbers in a single long cord: "2357111317192329…". At present every minion must draw a number from a hat. That number is the starting index in that cord of primes, and the minion's new ID number will be the next five digits in the string. And then if a minion draws "3", their ID number will be "71113".

Help the Commander assign these IDs by writing a part solution(due north) which takes in the starting index n of Lambda'southward string of all primes, and returns the adjacent v digits in the string. Commander Lambda has a lot of minions, then the value of n will always exist betwixt 0 and 10000.

— Test cases —
Input:
Solution.solution(0)
Output:
23571

Input:
Solution.solution(3)
Output:
71113

At its centre, the challenge here is to compute a long serial of primes. And someday you face this challenge, your goto algorithm should exist Sieve of Eratosthenes[3]. I was pretty sure Sieve would exercise the trick, but I had forgotten exactly how it worked, then I fired upward a Youtube video to become a refresher. With that, permit's build the solution.

Re-ID Solution

So, once the Sieve part is in identify, all nosotros need to exercise is

• Slightly change the Sieve part to produce a concatenated list of primes.
• Calculating the substring from this list from alphabetize to index + 5, every bit essentially this would give us the adjacent 5 dights from the cord of primes later the index. This is exactly the output ID commander Lambda is looking for.
• Furthermore given the constraints, this listing needs to be at least 10000 + 5 numbers long. And so with a scrap of beast forcefulness checking, finding out all primes until 206412, will be adept plenty for our use case.

And that's information technology. If you are interested in how I solved the other challenges, cheque out my repo.

In futurity posts, I will be going through the key insights/learnings for the solutions from the other questions I solved. I'll link them hither. To be notified of the aforementioned, consider following me on medium and subscribing to get an electronic mail of the same sent straight to your inbox! 😊

thompsonwassew.blogspot.com

Source: https://towardsdatascience.com/my-google-foobar-journey-2d02e8150158

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