The Nineteenth Byte

Python 2, 87 bytes, Sp3000, A083054 n=input() _=int(3**.5*n)-3*int(n/3**.5)######################################## print _ Not that hard, actually. Just searched for sequences that met the constraints until I found one that could be generated in the given space.

Sp3000

Yeah, I know. I found a third one myself soon after, so I'm kicking myself right now for not looking for other sequences first

:/

LegionMammal978

You might want to update the cop answer

Sp3000

Was doing (and now done)

LegionMammal978

11:55 AM

What was your original program?

Sp3000

I don't really want to post that one in case I make another cop using similar ideas :/

(was hoping it'd be a fun one but clearly I've botched that pretty quickly)

LegionMammal978

There's a bit of a tradeoff when being a cop:

You can list common sequence elements, which risks other, possibly shorter programs meeting the constraints;

or you can list uncommon sequence elements, which risks the sequence being determined too quickly.

Sp3000

Yeah :/ I'm almost tempted to just list enough terms to uniquely identify the sequence, but somehow that'd be no fun I think

(or would it be fun? Not sure)

LegionMammal978

I can help you with that

For this challenge, I wrote a small C program that searches for sequences given some elements

@Dennis Just yesterday, in fact, I saw that for the first time in an actual website.

Sp3000

Hm...

Nathan Merrill

12:03 PM

@KennyLau @MartinBüttner I wasn't the one who suggested disallowing no-ops (because its impossible to define a no-op). I did say that robbers should be allowed to use no-ops in their code

LegionMammal978

Yes?

Kenny Lau

12:13 PM

@LegionMammal978 How did you find that sequence?

LegionMammal978

@KennyLau With my C program

$ ./seqfind _ _ _ _ 2 _ _ _ _ 2 _ _ _ _ 1 _ _ _ _ 1 _ _ _ _ 1
A007061 matches
A026465 matches
A030561 matches
A040959 matches
A048220 matches
A073783 matches
A083054 matches
A096993 matches
A097026 matches
A135265 matches
A152735 matches
A181810 matches
A233138 matches
A242081 matches
A242082 matches
A245920 matches
A245933 matches
A251092 matches
A253641 matches
A266640 matches
A266685 matches

Kenny Lau

@LegionMammal978 Ah, meta-golf.

Sp3000

Hm... okay, what happens if you add a(30) = 3?

LegionMammal978

$ ./seqfind _ _ _ _ 2 _ _ _ _ 2 _ _ _ _ 1 _ _ _ _ 1 _ _ _ _ 1 _ _ _ _ 3
$ ./seqfind _ _ _ _ _ 2 _ _ _ _ 2 _ _ _ _ 1 _ _ _ _ 1 _ _ _ _ 1 _ _ _ _ 3
A101312 matches

Sp3000

Good enough

Adnan

12:16 PM

That is a nasty sequence haha

Sp3000

I'm reposting it, but to make it more fun you now have 3 less bytes

LegionMammal978

Yeah, sometimes you have to add another blank to account for offset 0 sequences

Sp3000

I'll post in a bit, but lemme see if I can golf this further first :P Feel free to think about how you would do that sequence in the template

zyabin101

@LegionMammal978 Is it closed source?

LegionMammal978

@zyabin101 Not at all

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(int argc, char **argv) {
    char *num;
    char *seq;
    char line[1024];
    FILE *db;
    int match;
    int i;
    int j;
    db = fopen("Projects/Evolved/bin/Debug/db", "r");
    while (fgets(line, 1024, db) != NULL) {
        match = 1;
        seq = strtok(line, " ");
        for (i = 1; (num = strtok(NULL, ",")) != NULL && match && i < argc; i++) {
             if (*argv[i] == '_' || *num == '\0')
                 continue;

Although you'll have to find the OEIS sequence dump yourself ;)

I just reused it from my Evolution of OEIS sequence suggestion program

Sp3000

12:24 PM

k, posted. Have at it :)

flawr

@LegionMammal978 Not enough golfed.

vote-to-close low effort

Kenny Lau

@LuisMendo is not in this chatroom?

flawr

Not right now.

source

shameless-self-promotion

no-rep-whoring

Sp3000

@LegionMammal978 But yeah, nice work with the searcher :) I wasn't sure whether to give the sequence away or not, but given the searcher it seems like difficulty via searchability won't cut it.

Can you add a keyword:nice to your search to narrow it down? (as an option, say)

LegionMammal978

No, the dump I have only contains the sequence elements themselves

formatted like:

Sp3000

12:29 PM

Ah, k

LegionMammal978

A269513 ,8,16,40,48,56,64,72,80,88,96,112,128,144,192,216,224,264,288,296,360,368,440,456,480,608,616,672,752,760,856,912,920,960,1128,1176,1216,1424,1432,1440,1464,1480,1552,1728,1872,

Sp3000

So it's not like it actually does networking to search, I guess

LegionMammal978

(in one line)

@Sp3000 Yeah, don't want to DoS their servers ;)

Sp3000

:P

Nathan Merrill

oooh, I think I solved CodeJam D

aditsu

12:33 PM

@NathanMerrill username?

trichoplax

@flawr Nice answer :)

Nathan Merrill

I haven't done it yet, but NathanMerrill

Optimizer

hahaha

aditsu

"Sorry, you can't have more than 30 friends at a time." >_<

Optimizer

irl?

aditsu

12:36 PM

lol, no, in the code jam scoreboard

ok I removed somebody :p

Nathan Merrill

initially I thought that the fact that G tiles simply get replaced with N gold tiles is irrelevant, but its the key to the who thing

Sherlock9

@xsot How? I thought the judge on the small input only tests for the small input test cases?

Sp3000

xsot means, assuming your small and large use the same algorithm, you can test your algorithm so that if it works on small it probably also works on large

aditsu

I did that for a problem, and although the algorithm is the same, the small solution crashed for some reason

I furiously recoded it in java and managed to confirm it within 8 minutes :p

Mars Ultor

@aditsu How did you find 30 people to befriend?

Agawa001

12:46 PM

that must be facebook

aditsu

@MarsUltor irc and this room

(from previous years)

LegionMammal978

I like to call the cardinality of ℕ the "fixed point of the successor function" because that's what it is

aditsu

oh and also a few friends irl (former colleagues)

Sherlock9

My brain is going to explode from it being so dense for these hints

LegionMammal978

@Sp3000 Please remember that the sequence I found has an offset of 1901.

Sp3000

12:49 PM

Were we counting offsets? I was really confused about that

LegionMammal978

Yes

So you have to use 1905, 1910, etc.

Optimizer

7

Sp3000

:/

LegionMammal978

@Sp3000 That post is still valid; you just have to change the function inputs to match.

Sp3000

Yeah, but it changes the byte count :/

Mars Ultor

12:55 PM

\o/ Creating a code jam library, reduced a solution from 240 to 133 chars

xsot

@Sherlock9 ^ What Sp3000 said. This is more relevant for D in particular since it's not easy to verify the correctness of the output locally

Luis Mendo

@KennyLau On the phone. I'll be here later

Kenny Lau

I'll be gone

LegionMammal978

@Sp3000 The shortest I can do, though, is

from datetime import*;_=sum([int(date(n,a,13).weekday()==4)for a in range(1,12)])

Sp3000

Yeah, the point is to do it a lot shorter than that, but if the program needs to account for the offset then it's not as fun :/

Sherlock9

1:05 PM

Except, of course, that my algorithm is having a hard time with medium inputs too and I'm getting really, really frustrated

I should not need itertools. I should not be checking every string K^C but I can't think of anything else!

Nathan Merrill

@Sherlock9 I've actually found a formula that works

you should never need to iterate

the fact that G gets replaced with all G is key

quartata

@ChrisJester-Young Interesting. Thanks.

@ChrisJester-Young Huh, what does partition do?

I think I get how that one works but it seems a little strange.

Sp3000

1:24 PM

@LegionMammal978 Yeah, if it's okay I might keep it deleted sorry - the offset's part of the fun and I also just found this...

quartata

Actually I just realized the real proper way to do it would be to find a way to interweave the two lists together.

If I can take '(1 2 3) '(4 5 6) -> '(1 4 2 5 3 6) then I can just iterate through that instead of having to do this

Mars Ultor

looks at past Code Jam solutions

Wow, C++ is so verbose

Sherlock9

@NathanMerrill I'd say I should sleep on it, but the contest ends 9 am tomorrow and I may very well sleep through the end

CoolestVeto

@EᴀsᴛᴇʀʟʏIʀᴋ ihaichu

Sherlock9

And I want to get D, and all these hints: "there's a linear algorithm", "base K", "G gets replaced with all G" are not making it in >_<

Mars Ultor

1:26 PM

@Sherlock9 So

zyabin101

@CoolestVeto >.</

Mars Ultor

@Sherlock9 base 3 complexity 3 = 123123123123123123123123123, 111222333111222333111222333, 111111111222222222333333333

Sp3000

(so many spoilers :/)

xsot

@Sp3000 My bad

Sp3000

@xsot Nah it's fine. At least yours was more subtle :P

Mars Ultor

1:29 PM

G gets replaced with all G means g overrides l

@Sp3000 Don't look

quartata

Wait can you map in parallel

oh that's awesome

Sp3000

Doesn't matter to me now anyway, but I'll go, er, warn Martin

quartata

All I have to do is map cons over them and flatten

Sherlock9

We may need to move this discussion though or drop it

Mars Ultor

And Dennis, Maltysen, Mego, Kenny and Chris

zyabin101

1:31 PM

@Sherlock9 The contest ends 5 am tomorrow here.

CoolestVeto

@Sp3000 wishes for >!

Sp3000

Hmm that wouldn't be too bad in chat, actually

zyabin101

>! spoiler

Yup, doesn't work.

Nathan Merrill

@Sherlock9 Would checking the first K tiles work?

Sherlock9

@NathanMerrill For small. And I think I just figured it out. I should try to figure it out myself in the next round :$

THough I have been trying

Nathan Merrill

1:36 PM

er, that's not what I'm saying

would having the students check the first K tiles work?

every time

Sherlock9

Oh

Mars Ultor

@Maltysen @Mego anyone who knows python/java please try to do some past problems if you want to. send a PR with your solution here

past problems here

aditsu

@NathanMerrill hey I found a file with user names, you used a different one last time :/

that may be another way I got to 30 friends :p

Nathan Merrill

@aditsu yes, on a different email

CoolestVeto

in PPCG Minecraft Server, 12 secs ago, by CoolestVeto

I'm missing: 27 stacks of bread, 20 stacks of baked potatoes, 9 stacks of uncooked potatoes, 5 stacks of hay bales, 4 stacks of wheat, 8 stacks of coal, 18 stacks of beets, 9 stacks of carrots, and 6 stacks of seeds.

ಠ_ಠ

Nathan Merrill

1:43 PM

I used the new email in case google is looking into my account (I have an interview on Wed)

aditsu

ooh

Sp3000

1:55 PM

@MarsUltor You can download peoples' past solutions via the scoreboard

aditsu

there's also go-hero.net/jam with all past solutions and statistics

quartata

2:24 PM

@ChrisJester-Young Why doesn't call-with-values seem to work with map? For example this doesn't work: (call-with-values (partition even? (range 1 5)) (lambda (x y) (map + x y)))

Throws an arity mismatch

zyabin101

Which people did join the code jam from the last time I asked? What are their usernames?

aditsu

well, I'm aditsu

zyabin101

@aditsu Added. Are you in Romania?

aditsu

no, I'm from Romania

zyabin101

@aditsu Okay.

@Doorknob what is your code jam username?

Is it right that Doorknob's code jam username is KeyboardFire?

RSMFTD

in Sandbox, 1 hour ago, by RedRiderX

> foo extra bar
ಠ_ಠ

extra foo

> ಠ_ಠ

muddyfish

2:46 PM

do any of you guys know some simple electronics?

trichoplax

How simple is simple?

muddyfish

like simple enough to answer this

zyabin101

@trichoplax Simple.

muddyfish

am I right in saying that the effectine resistance of a capacitor is 1/f?

where f= frequency

LegionMammal978

How does one use the 05AB1E TIO?

trichoplax

2:48 PM

I don't think it is dependent only on f

muddyfish

joy

I'm trying to write up how a resistor and a capacitor behave whilst in parallel with varying frequencies

trichoplax

physics.bu.edu/~duffy/semester2/d21_effectiveR.html

thanks?

Does it help?

@zyabin101 yeah

2:51 PM

just checking now

trichoplax

You're dealing with AC, right?

zyabin101

@trichoplax All Clear?

trichoplax

Alternating Current

Adnan

@LegionMammal978 What do you mean?

LegionMammal978

@Adnan It doesn't seem to be accepting input.

muddyfish

2:53 PM

yay

java crashed my browser!

Adnan

Hmm, can you give an example?

LegionMammal978

My program is LŸæO, don't see anything wrong with it

zyabin101

@LegionMammal978 Give it as command line arguments.

Adnan

@zyabin101 no

LegionMammal978

@zyabin101 Then it still doesn't output anything

zyabin101

2:54 PM

@Adnan Then IDK ¯\_(ಠ͜ ಠ)_/¯

@LegionMammal978 ^

Adnan

O only works on lists containing ints. You can use the debug flag though

You are really close :p

LegionMammal978

@Adnan Found it, just had to flatten

trichoplax

@muddyfish If you want more than just my wikipedia based answers, you could try Electrical Engineering

Adnan

Nice, great job :)

LegionMammal978

Wait no it still outputs 0 in input 1

Adnan

2:57 PM

Oh

LegionMammal978

LŸæ`O should be working...

Luis Mendo

@muddyfish Apart from the omega times C factor, the result is imaginary, so it's impedance (reactance), not resistance. You need to deal with complex numbers in order to "mix" capacitors and resistors

LegionMammal978

Oh, flatten also acts as union facepalm

Adnan

@LegionMammal978 Hmm, ` is just a flatten operator, not deep flatten :p

And I messed up the font again

LegionMammal978

@Adnan Well, the list is only two levels deep

Like [[1, 2, 3], [4, 5, 6]]

Cᴏɴᴏʀ O'Bʀɪᴇɴ

2:59 PM

This new cops n' robbers challenge is so much fun :D

Adnan

Yes, so what remains is [1, 2, 3], [4, 5, 6] and that is the stack

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