My mom and I have had a couple conversations recently about how I went from being somewhere between introvert and extrovert to being almost full introvert. I mentioned that I'm much more social online, and showed her last week that I have over 20k messages in this room.
@Calvin'sHobbies It's not about such a popular story, and it's about a certain thing that's left as a subject of lots of suspense throughout the first half of the book
I am learning English. I and my friends argue and confuse about about a thing:
Let's assume I have a guide to cut 2 sticks
Stick A should has 100cm of length. Stick B sholud has length higher than 30% of stick A.
So if we calculate, 30% of stick A is 30cm.
Is it:
Stick A: 100cm, stick B = S...
Okay, I'm gonna go ahead and write the challenge without relating it to the book, but I'll stick a non-spoilerish reference in the front like "if you've read this book, this may seem familiar" or something :P
It would probably be better if just all the statements were true, so with 2A2=4 you would be able to figure out that A is either + or *, and with 3A0=3 you would know that A is + or -, but combining them you would be able to figure it out"
Detour, 17 bytes
<?\$;p>R*.
\ 0/
This is non-competing, as I just finished the language today.
There's no good way to explain it, the website will give a visualization of the data flow at runtime.
Write a piece of code that is executable in at least three different languages. The code must output the integer 1 in language number one, 2 in language number two, 3 in language number three etc.
Rules:
The output must be only the integer, but trailing newlines are OK.
The code can't take in...
@feersum Because there are efficient primality tests for special cases like this one. For Mersenne numbers, there's the Lucas-Lehmer test. With a ban on built-ins and/or a time limit, it's a completely different challenge.
Help GIMPS find Mersenne primes!
There has recently been a discovery of a new prime number: 2^74207281-1. This is the biggest prime number to date and broke the previous 3-year record holder by over 4 million digits!
Your job will be to help GIMPS (Great Internet Mersenne Prime Search) find som...
Well, not any recursive sequence. s_0 = 4 and s_{n+1} = s_n^2 - 2.
(Not to be confused with Lucas pseudoprimes, which are something else entirely.)
@GamrCorps There are only 11 Mersenne primes that fit in a signed 32-bit integer, and less than 32 Mersenne numbers. With your restriction to the language's native integer type, I don't think it makes sense as fastest code.
@GamrCorps Also, this is somehow unrelated to your challenge, but GIMPS isn't about finding the nth Mersenne prime. It is currently unknown how many Mersenne primes are smaller than 2 ^ 74207281 - 1.
We only have 9 questions that involve lasers. Not sure if one of those is similar to what you have in mind. For starters, how would you represent those mirrors?
i feel like there should be a fairly simple formula if you draw out the phantom mirrors to get a half-circle of mirrors placed radially
I'm getting that with two mirrors of length L, at distance D from the intersection point, and angle x, the number of reflections is floor(2/x*arccos(D/(D+L)))
@quintopia Jelly will win since it has two-byte arccos and implicit input. Seriously also has one-byte arccos but not implicit imput, and it needs to save D, costing a byte. APL's arccos is 3 bytes long. Pyth's arccos is 3 bytes, but it doesn't have implicit input either. TI-BASIC has one-byte arccos but input will cost 5 bytes in addition to accessing the variables, so it's not winning.
As far as I know, in US, grip-and-turn style door knobs are still the most popular, as opposed to lever-style handles, which dominate in the rest of the world.
Is there some UX advantage to door knobs that I am not aware of, which is the reason for keeping them around?
Edit:
To clarify the dif...
It's composed by @SmokeDetector, a bot in the Tavern of Meta that reacts to certain filters. When it finds a naughty post, it posts it in chat so that the admins of Stack Exchange can wipe it. Or not.
I'm not entirely sure how to phrase this, so please bear with me. I have a modified Julian Day Number function that says day 0 is January 7, 1970 (it's the first new moon of 1970, and this is for the moon phase challenge)
I want the calendar to calculate moon phases to start about twelve hours before the new moon on January 7, 1970 which would 0835 UTC. Currently it starts at midnight UTC on that day, 30900 seconds off, give or take. Do I add or subtract 30900 from my code to make it right?
@Quill And why does every american doors jam in one way or the other? Are americans unable to make doors that just fit exactly how they are supposed to fit? And why do they still used the crappiest door locks available?
Introduction
tl;dr
In this challenge you have to calculate the moon's phase for a given date.
This challenge is inspired by the game psycho social audiovisual experiment "Superbrothers: Sword & Sworcery EP". In S:S&S EP the moon's phases are important to the outcome of the adventure as some ...
@flawr middle row turn clockwise. Middle column turn clockwise. Middle row turn counterclockwise. Middle column turn counterclockwise. You can change either the row or the column to go counterclockwise to clockwise.
Just experiment with the different combinations to get exactly what you want.
Introduction
There is an Apple tree trunk positioned at -2 to 2, where some apples get down around:
| |
| |
<-------|---|------->
-2 2
Everyday, some n apples get down. Each apple has its x-axis and takes its direction to the ground.
But if there is already anoth...
ok so.. I have two understandings of fourier transforms (FT). On the one hand the FT simply evaluates a polynomial and n roots of unity. This gives a point value representation. The inverse Fourier transform then lets us go from n evaluations at roots of unit back to the coefficients of a polynomial
One the other hand, when you apply the Fourier transform to an audio signal you get a representation in terms of the sum of sine and cosines
Just keep in mind: The FT transforms a signal (doesn't have to be real, it can be complex) into its frequencies (complex too) and vice versa. The IFT is basically the same as FT (apart from some constants).
So if you evaluate the FT at a certain point, you get the amplitude of that frequency
A vague question of Kevin Lin which didn't quite fit at Mathoverflow:
So ... what is the Fourier transform? What does it do? Why is it useful (both in math and in engineering, physics, etc)?
(Answers at any level of sophistication are welcome.)
This guy at my office keeps putting together these workshops on Scrum, and I can't help but think "Wow, how are you guys who keep doing all of these workshops so far behind my team, who never attends any of your workshops?"