Lot of cities in my area have already broke records for rainfall this month two days ago. And it has rained every day since then. And it's going to rain today again.
And the best part of this is that it's been sunny almost every day. It pours down heavy rain for ten minutes to an hour, then it stops and the sun comes out.
This Stack Snippet draws an aliased white rectangle on a black background given parameters for its dimensions, position, angle, and the grid dimensions:
<style>html *{font-family:Consolas,monospace}input{width:24pt;text-align:right;padding:1px}canvas{border:1px solid gray}</style><p>grid w:<...
So, let's say you have a safe that takes in an X digit number to unlock.
However, whoever designed the safe was lax on programming and makes it so any consecutive X numbers that match the combo is appropriate to unlock the safe.
So if the code is 1121 and you hit 111121, it'll unlock the safe.
> The sequence can be used to shorten a brute-force attack on a PIN-like code lock that does not have an "enter" key and accepts the last n digits entered. For example, a digital door lock with a 4-digit code would have B(10, 4) solutions, with length 10000. Therefore, only at most 10000 + 3 = 10003 (as the solutions are cyclic) presses are needed to open the lock. Trying all codes separately would require 4 × 10000 = 40000 presses.
I answered the question by the link here, but I actually didn't read any of the conversation after your message here. (I happened to have the knowledge of De Bruijn sequences before, please don't blame me for just stealing the link to Wikipedia + the answer from @PhiNotPi :P)
I wonder if it would be any more interesting if we were looking for a subsequence instead of substring. Say the lock, once accepting a correct digit, doesn't reset and just ignores input until the next correct digit. (Terrible lock design, but whatever)
So then for (2,2), 0110 would work.
Nevermind, that ends up being really stupid. Forget I talked.
hmmm, surely that must have been studied... but due to the inconsistent use of "substring" and "subsequence" by some people my googling efforts are just turning up normal de bruijn sequences
I guess it would be more interesting for arbitrary sets of strings
I really don't get Area51 notifications
for my Nice Answer badges I only got a notification bar at the top when visiting Area 51. now I just got yearling which appeared in the normal achievements tab, but I didn't get the notification bar on area 51
The seam carving algorithm, or a more complex version of it, is used for content-aware image resizing in various graphics programs and libraries. Let's golf it!
Your input will be a rectangular two dimensional array of integers.
Your output will be the same array, one column narrower, with one ...
I actually expected to see some really short solutions quickly.
As it turns out, finding the minimum sum is super easy in a bunch of languages. Actually keeping track of the seam that generates that sum and removing it... not so much.
I spent about five minutes trying to come up with a way to word the challenge to exclude that approach in CJam and other languages with a "convert this block of code to its string represenation" function
Write a program that outputs a list of the number of occurrences of each unique character in its source code.
For example, this hypothetical program {Source_Print_1}; should produce this output:
; 1
P 1
S 1
_ 2
c 1
e 1
i 1
n 1
o 1
p 1
r 2
t 1
u 1
{ 1
} 1
The formatting should match this examp...
Two years ago, we rolled out some significant changes to closing, along with a massive number of changes behind the scenes to clean up the supporting logic that had grown crufty over the years. As with many ambitious projects, this one quickly pushed the limits of its 6–8 week implementation sche...
But especially links to the custom close reasons at the bottom. I can imagine opening the tools thing to see "I've voted to close this as off-topic because you're stupid", only to not be able to find what post it was on :D
I would if I had an actual example. Apparently people flag them and they get cleaned up, making it a non-issue. I was sure I'd find a good example on SO, but they're pretty tame, tbh.
ppcg esolang stupid idea: define a language in which every unique string of characters defines exactly one specific program that solves a challenge on ppcg, with the language spec updated just a little too late to use it in any challenge unless an exact duplicate is posted later
@Optimizer he's hiding or conserving heat, I think. unless my snake-fu is rusty, I think he can only strike from that position as far as the central S-shape reaches, not the coiled bits.
Prove Your Language is Turing Complete
Write the shortest code possible to prove that your language is Turing Complete. However, if the programming language is not Turing Complete because of something like limited access to memory, just state so.
You can prove your language is Turing Complete i...
@Sparr but that still only allows you to have one marble per cell
Just in case you didn't know already, we have a fairly new type of challenge: cops-and-robbers
I enjoy these challenges very much, but I don't know if the current format (cops post answers, robbers post comments) is optimal.
I see the following problems, in descending order of importance:
Com...
Objective:
Code two programs where each of the programs outputs both sourcecodes
interlaced per character, a Double-slit Quine. The output from a Double-slit Quine
is starting with the first character from the sourcecode of the first
program. If the sourcecode of one of the programs is ...
I hate combined answers everywhere on StackExchange
lots of meta sites endorse them, which really annoys me
it breaks the voting system
it interferes with the comment system
oh, the top/accepted answer has 9 separate solutions in it? let me flip some coins to decide which of them to use
@MartinBüttner ^^ this is very very slightly aimed at your OEIS-aggregate answer to my meta question about math contributions.
if that answer grows, it's going to contain some very notable things, and some very unimportant things, and I am annoyed that I can't vote up the notable things.
Inspired by http://puzzling.stackexchange.com/q/626
In your adventures you arrive at a series of 7 bridges you have to cross. Underneath each bridge lives a troll. In order to cross the bridge, you must first give the troll a number of cakes as a percentage of the number of cakes you are carry...
Okay, I recently wrote a Javascript Rubik's Cube scrambler that outputs a 25-move scramble. It's 158 bytes, but I feel like the code can be shortened further. The Gist is here, but for reference, I have the formatted code:
function(){
for(var a=0,s=y=r=[],m='RLUDFB'.split(''),f=["'",2,''],x=Ma...
This Stack Snippet draws an aliased white rectangle on a black background given parameters for its dimensions, position, angle, and the grid dimensions:
<style>html *{font-family:Consolas,monospace}input{width:24pt;text-align:right;padding:1px}canvas{border:1px solid gray}</style><p>grid w:<...
The seam carving algorithm, or a more complex version of it, is used for content-aware image resizing in various graphics programs and libraries. Let's golf it!
Your input will be a rectangular two dimensional array of integers.
Your output will be the same array, one column narrower, with one ...
Prove Your Language is Turing Complete
Write the shortest code possible to prove that your language is Turing Complete. However, if the programming language is not Turing Complete because of something like limited access to memory, just state so.
You can prove your language is Turing Complete i...
Just in case you didn't know already, we have a fairly new type of challenge: cops-and-robbers
I enjoy these challenges very much, but I don't know if the current format (cops post answers, robbers post comments) is optimal.
I see the following problems, in descending order of importance:
Com...
Objective:
Code two programs where each of the programs outputs both sourcecodes
interlaced per character, a Double-slit Quine. The output from a Double-slit Quine
is starting with the first character from the sourcecode of the first
program. If the sourcecode of one of the programs is ...
Inspired by http://puzzling.stackexchange.com/q/626
In your adventures you arrive at a series of 7 bridges you have to cross. Underneath each bridge lives a troll. In order to cross the bridge, you must first give the troll a number of cakes as a percentage of the number of cakes you are carry...
Okay, I recently wrote a Javascript Rubik's Cube scrambler that outputs a 25-move scramble. It's 158 bytes, but I feel like the code can be shortened further. The Gist is here, but for reference, I have the formatted code:
function(){
for(var a=0,s=y=r=[],m='RLUDFB'.split(''),f=["'",2,''],x=Ma...
