>optimal solution in less than a minute

you're interviewing wrong and i'm surprised that you haven't figured it out given 200 attempts. put yourself in the shoes of the interviewer - interviews aren't their main focus in the company and hence they're not invested in being excellent interviewers. they're most likely trying to do a good enough job such that it counts towards promotion and simultaneously not have a horrible time during the interview. so they have roughly a script that they'll follow

1. give the imprecise problem statement

2. give the opportunity for clarifying questions (points added or subtracted from interviewee for asking relevant/irrelevant/interesting/mundane question)

3. give the opportunity for naive solution (points added or subtracted for facility in implementing and runtime discussion)

4. introduce challenge portion (optimization or constraint or whatever)

5. give another opportunity for clarifying questions

6. give opportunity for talking through a solution

7. give opportunity for writing solution

assuming you make it this far

8. give the opportunity for discussion of trade-offs in time/space/code complexity/latency/etc.

that's 6 opportunities to demonstrate that you're smart, fastidious, affable, etc but only 2 of them are really technical. if you're aiming for writing the best/most optimal solution as fast as possible then you're aiming for the wrong thing - it's not a standardized test but an interview (i.e. two people are involved). you should be aiming to impress the interviewer! those aren't the same (the first is a component of the second).

if you'd you should put your contact info either here in a response or in your profile and i'll reach and we can chat about interviewing (i'm not a coach or a business but i do interview well so maybe i can help you a little).

"Did you win the Putnam?"

Yes, I did.

I teach and coach people to get jobs through performance and it works.

Schools teach people to react, take tests, and show how great they are. For a posted opening, you're presenting yourself as a commodity -- a slightly shinier one, you hope. It's based on compliance.

Most analytical, geeky types got a lot of schooling. After decades of it, most people have learned that model without awareness of alternatives.

If you want to avoid challenges in life and just get a job so you can retire 50 years later with nothing remarkable in between, that strategy works.

What Ryan described -- to audition -- is standard in other fields, such as sports, acting, singing, and other active, social, emotional, expressive, performance-based (ASEEP) fields. No actor won an oscar for his or her GPA. No athlete won a championship for being president of a student club.

In ASEEP fields, your performance matters. Sadly, many in business continue to think and act on a compliance-based model. Those who start from a performance-based model find and create opportunities to excel.

I'll always remember how a client told me he met a guy running a business in a field he wanted to move into. He told me he first got to know the guy to make sure he'd like working with him. He then told him his passions and hobbies in that field, then that he had zero professional experience, and then, as he told me, "I led him to hire me."

That's leadership. The guy hired him, saying "I can teach you this field, but I can't teach getting it and you get it." (Incidentally, what he called "getting it" is what I taught him -- you can teach it, just not through a compliance-based model.) So he got paid to learn the new field. Not long after he started new initiatives in that business.

Fascinating. I have a keen interest in Shamanism and more patience for "woo-woo" here than most. Navigating your dream state is a mighty Shamanic concept. It is one of two Shamanic practices that people here will entertain. The other is the idea of the memory castle.

New technological approaches like this will help us peel back the veil of the tangible, 'ordinary' realities of which we are comfortable. The world will be a much more funky and weird place once we realize there are non-ordinaries realities that we can explore, too.

Can someone explain to me why this has (so many) upvotes? This is like elementary undergraduate econ stats and kind of trivial?

There's very little content either, it's literally a reformulation of the formula, no interesting graphs or geometric interpretation. What I expected from a title like "Linear Regression By Hand" was the minimization of some quadratic error function, by hand (i.e. using pencil and paper).

Anything with the phrase (paraphrasing) "but I must warn you, you must be surrounded by evolved people" sounds so incredibly condescending and pretentious it really shows how these people see themselves as superior to others, like your friend who travels a lot and brings it up all the time. Except his stories are rational and meaningful, while stories about tripping balls are so subjective, they're meaningless.

Yes, I'm sure it was a positive experience, but the idea that you can learn wisdom and maturity via chemistry, well, that idea never panned out. Instead you get the typical empty-head drug talk about "seeing god" and "being nothing." And for all the elaborate salesmanship, what do these people get in the end? They're extremely ineloquent and whatever wisdom is purported to be there, just doesn't seem to be there. They've obviously invested into some kind of "rebel" personality and drug culture panders to them. I should know, I was invested in drug culture myself for longer than I care to admit on the internet.

Meh, the counter-culture petered out for a reason. Turns out ingesting random chemicals isn't the big statement so many thought it was. There's no shortcut to being an interesting and clever person. You gotta put the hours in.

After reading a fair amount about Stoicism and still being unclear, I've found a good summary in Adam Smith's almost forgotten classic, "The Theory of Moral Sentiments" (1759) [1]:

"Human life the Stoics appear to have considered as a game of great skill; in which, however, there was a mixture of chance [...] In such games the stake is commonly a trifle, and the whole pleasure of the game arises from playing well, from playing fairly, and playing skilfully. If notwithstanding all his skill, however, the good player should, by the influence of chance, happen to lose, the loss ought to be a matter, rather of merriment, than of serious sorrow. He has made no false stroke; he has done nothing which he ought to be ashamed of; he has enjoyed completely the whole pleasure of the game. [...]

Our only anxious concern ought to be, not about the stake, but about the proper method of playing. If we placed our happiness in winning the stake, we placed it in what depended upon causes beyond our power, and out of our direction. We necessarily exposed ourselves to perpetual fear and uneasiness, and frequently to grievous and mortifying disappointments. If we placed it in playing well, in playing fairly, in playing wisely and skilfully; in the propriety of our own conduct in short; we placed it in what, by proper discipline, education, and attention, might be altogether in our own power, and under our own direction. Our happiness was perfectly secure, and beyond the reach of fortune."

[1] http://www.econlib.org/library/Smith/smMS7.html

I'll be expecting my RSUs from Google for telling them this exact strategy in my PM interview 2 years ago when I was asked "What would you do with Google Glass?". Then again enterprise is a fairly obvious answer even before they tried the consumer angle. But, if they offer Gmail for people that colonize the moon, (another interview question I got), then I'm definitely going to need some retribution for telling them how to do that too :-P

Always liked this stealthy prospect finding method. Here's another few (best for B2B):

1. If some change happens at one of your competitor's product (got acquired, changed a beloved feature, etc.), go through threads on public forums discussing it. You'll find a lot of current users (ie customers to poach) of that product. A recent example: Atlassian acquiring Trello.

1b. Also, look through the comment sections of news sites that reported this change. You'll also find tons of current users there.

2. Go on user submitted product review sites. Lots of them out there for different types of products: Chrome extension review page, Capterra, G2 Crowd, etc. Approach the users who left reviews expressing dissatisfaction with the competitor product. Or users who use a complimentary product.

3. If a competitor product hosts customer sites on their servers (Shopify, etc.), you can reverse lookup their IP to find all of them.

Then it's a matter of introducing your product with a semi-personalized cold email, reassuring the prospect you have the competitor product's most vital features and you also do XYZ better than them. Here's a template: http://www.artofemails.com/cold-emails#competitor

I'm glad that worked for you. I heard somewhere in my teens a doctor who said essentially that we spend our adult lives trying to recreate our childhood relationships and if we find our adult relationships lacking, that connection is the first place to investigate.

Education at this level is a "who can survive the most unpleasantness" competition. High school students work their asses off to get into highly selective colleges. Highly selective college students work their assess off to get into highly selective grad schools or employers (investment banking, consulting, prestigious tech companies). Students of highly selective grad schools work their asses off to get into the vanishingly few secure, living-wage jobs in their fields.

At each stage, the purpose is the same - to prove that you are more deserving than your peers of a seat in the next stage, because each stage has fewer seats than the last.

If you value your present well-being over advancement (and therefore future well-being), don't put yourself in a competitive educational environment with the goal of "winning" (i.e. high GPA). If you have certain career tracks in mind, sleep deprivation, poor mental health, and low quality of life in the short and medium terms are table stakes.

I enjoyed my time at such a place once I had a good relationship with a tech company (now my employer) and no grad school ambitions. My friends headed for the sciences could not have optimized for their present happiness without giving up their dreams.

Aside: ridiculous how influential k5 was on my life. Their first article on coffee turned me into a coffee snob before third wave cafes became the rage. The article on ultralight backpacking started a lifelong obsession, eventually leading me to thru-hike the Pacific Crest Trail.