lsusr

lsusr's Comments

What Surprised Me About Entrepreneurship

The global dog population is estimated at 900 million. There are two species of wild wolves: red wolves and grey wolves. Red wolves are critically endangered.

It's hard to find exact numbers on grey wolf populations in 2020. According to Wikipedia, grey wolf populations were estimated to be 300 thousand in 2003.

Which books provide a good overview of modern human prehistory?

I too was disappointed by the lack of rigor in Yuval Noah Harari's Sapiens. I felt Paleontology A Brief History of Life by Ian Tattersall covered the same material in fewer pages to a higher level of rigor. However, Paleontology might not be the book you're looking for because it covers pre-human natural history too.

I get a lot of quality information from modern ethnographies of hunter-gatherers such as Nisa: The Life and Words of a !Kung Woman by Marjorie Shostak and The World until Yesterday: What Can We Learn from Traditional Societies? by Jared Diamond.

3 Interview-like Algorithm Questions for Programmers

Yes. They move independent of which character it is.

3 Interview-like Algorithm Questions for Programmers

This question isn't about integers "given no assumptions". It's about the int primitive in Java.

3 Interview-like Algorithm Questions for Programmers

If you happen to know the answer already then the question is ruined. In this way, every algorithm puzzle in the world can be ruined by trivia. For an algorithm question to be interesting, I hope the reader doesn't already know the answer and has to figure it out her/himself. So in questions #1 and #3, I'm hoping the reader doesn't know the relevant trivia and will instead independently derive the answers without looking them up.

I'm not trying to ask "Do you know how Poland cracked the Enigma?" I'm trying to ask "Can you figure out how Poland cracked the Enigma?"

I don't grade these questions. These questions are for fun and self-improvement. Though I could imagine a timed written test with dozens of questions like this where the testee gets one point for each correct answer and loses one point for each incorrect answer. A sufficiently large number of questions might help counteract the individual variance.

3 Interview-like Algorithm Questions for Programmers

Fixed typo.

Let's imagine the daily code the machine is set it with is AAA. Would this turn the plaintext "X" into the 'ciphertext' "X"?

No, for a couple reasons.

First of all, each of the rotors have a different wiring. For example, in the first rotor, A might be wired to B and B might be wired to M.

Secondly, the reflector makes it impossible for any letter to be mapped to itself.

You are correct that the plaintext AAA is unlikely to be encrypted into the same letter multiple times such as BBB, due to the rotating rotors.

Makeshift face touch warner

As one of the Immutouch founders, I think this is really cool[1]! What is the Japanese in the background?


  1. Even though ours is more accurate. ↩︎

What are good ways of convincing someone to rethink an impossible dream?

The two most important things to understand about startup investing, as a business, are (1) that effectively all the returns are concentrated in a few big winners, and (2) that the best ideas look initially like bad ideas. ― Black Swan Farming by Paul Graham

I've known many people like you describe. One was an MBA who earns at least a quarter of a million dollars per year as a manager at a major tech company. Another is a former CEO. A third wrote software for a quantitative training firm. They all tried to start startups. They said lots of incorrect things to me. For example, the MBA once lectured me about how The Art of War is irrelevant to the study of business strategy.

Nothing I said ever convinced these confident people they were wrong. I quietly started my own startup. One after another, all of their businesses failed, often after wasting lots of money. Meanwhile, my startup chugs along.

Most of them learned their lesson and quit the startup game. Except the most capable one, who learned a different lesson and joined my startup as a co-founder.

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