I started trying to read this as a solution to day14 and my brain started to hurt lol.. need more morning coffee

another nice use of tree-seq, @bhauman!

i went the loop/recur route again for my flood

Is it wrong that I as someone who likes coding have an aversion to binary numbers? Two days in a row 😞

uh oh

40,000,000.. lol

hmm .. xor for speedup maybe?

ok, not too slow.. I'm sure there's room for improvement though!

Wow. I love clojure.

The binary isn't too bad here, thankfully.

today was easy, luckily

i'm learning that lazy sequences are slow

and recursion is preferred for this kind of problem

but not as nice to look at

@ihabunek what kind of performance are you looking at?

with lazy seqs

for me lazy-seq + count is 20 seconds range

I got 11 for part 1, 7 for part 2

I’m using loop recur + iterate

for reference: pypy loop with generators is instantaneous

like below 10ms?

no, 0.7 seconds for part-2, with pypy day15.py so including startup time

I'm getting around 30s for both parts. Using lazy-seq for generators

I'm getting 7s for first and 5s for 2nd using lazy; ~1s using recursion for first part

Huh. Can I see your code?

https://github.com/ihabunek/aoc2017/blob/master/src/aoc2017/day15.clj

Mine ^

https://github.com/minikomi/advent-of-code/blob/master/src/advent/2017/day15.clj

Have not used iterate before. Will look into it

good one to use for these kinds of "feedback" problems

oh, i like your lower-bits fn, stealing that 😛

@minikomi your implementation is not correct

oh?

try it on A: 512 and B: 191

for part2

should be 323, yours gives 301

weird

what's gone wrong?

for part 1 - 567?

https://github.com/minikomi/advent-of-code/blob/master/src/advent/2017/day15.clj#L28 that drop should be on lines 39 and 40

I had the same problem in my code, took me some time to find the problem 😞 (and some attempts typing the wrong answer 8))

Can you explain conceptually what the difference is?

first: part1 is also not correct but, there it doesn't matter, because there is no filtering involved, and the start values do not have the same 16 lower bits. Your (and my) code generates 277, (* 277 16807) and so on, but the start value should not be in the generated steps (check with example in problem). For part 2, the modulo 8 and 4 checks allows the start value for input 512 and the pairs are of by 1 for the complete range

oh, i see, i want to drop the first generated value - since they're seeds and not generated, but by having the drop where i had it, it drops the first filterted generated value

no it compares the wrong values for the complete range

Btw, here’s my code: https://github.com/borkdude/aoc2017/blob/master/src/day15.clj I think it could be optimized if I would loop/recurify the ranges as well

ok, moved the drops inside the filters -- fixes the part2 for the seeds you gave

day 15 from me: https://github.com/skazhy/advent/blob/master/src/advent/2017/day15.clj currently ~ 18 seconds for 1st / 10 for 2nd.

just got lucky with my seeds i guess 😛

I learned that iterate doesn't give (f x) (f (f x)) but x (f x) 🤓

So… it turns out to be this sequence: https://en.wikipedia.org/wiki/Lehmer_random_number_generator

nice find

Hi all! I had to skip yesterday because I was travelling, but I’m now all caught up. Day 14: https://github.com/orestis/adventofcode/blob/master/clojure/aoc/src/aoc/2017_day14.clj Day 15: https://github.com/orestis/adventofcode/blob/master/clojure/aoc/src/aoc/2017_day15.clj

@borkdude looking at your implementation of multiple-of, what's wrong with (zero? (mod x y)) ?

@ihabunek nothing, but this is slightly faster 🙂

ok, i guessed as much 🙂

Could be even faster when you inline 4 and 8

hm, quick-bench sounds interesting

would partial application be as fast as inlining?

no, it would still do the calculation when you call the partial

My day14 part 2 (flood fill) is at 7 seconds, using mostly plain sets.

i "cheated" on day14... used a transient set, and it's well under 1s 🙂

i guess localized mutability is ok though

For today, 5s and 7s.

@orestis cool. Wonder why my part 2 is faster than part 1, but it may be the input

Ah, iterate was what I should use.

I was googleing “clojure reduce infinite sequence” 🙂

iterate is my function of the day as well

@ihabunek Better example:

boot.user=> (defn inc* [x] (println "inc") (inc x))
#'boot.user/inc*
boot.user=> (defn f [x y] (let [x' (inc* x)] (+ x' y)))
#'boot.user/f
boot.user=> (f 1 1)
inc
3
boot.user=> (def g (partial f 1))
#'boot.user/g
boot.user=> (g 1)
inc
3

yes, i understand

makes sense

basically it only binds one of the inputs

I wonder if there is a faster way of comparing the lowest 16 bits than (== (unchecked-short ..) (unchecked-short ..)), maybe something using xor, or maybe it already does that on a lower level

i think my code is slow because of the way i use sequences more than comparing bits.

does this slack have a bot which runs clojure code like the irc channel does?

cool 😄

@ihabunek how does that work again?

/clj (println 1)

thanks

takes a little while though

and now let's try /clj (range) 🙂

i'll be good and not do that 🙂

using unchecked-short instead of (bit-and a 0xffff) does nothing for my performance

actually, it's slightly worse 🙂

@ihabunek it’s probably ok

oh no…

hah

😄

sorry… I can’t remove it…

now you know how to DOS this slack

who is the admin of this channel? 😉 @pvinis can you remove the range…

@borkdude what do you get by prefixing things with ^long

just so it doesn't use int?

@ihabunek evaluate the settings from the comment section at the bottom, then you’ll see warnings about boxing

so it’s to prevent boxing

ah, ok

Terribly sorry for the long output by range… didn’t know it would consume that much estate… pinging an admin who can remove it.

i disovered parinfer for sublime text and don't know how i ever managed to code clojure before that

i'm guessing half people here are on emacs

I’m using Cursive in IntelliJ and it also has parinfer

Although not the latest and greatest version 3

btw here’s my solution for today https://github.com/axelarge/advent-of-code/blob/master/src/advent_of_code/2017/day15.clj

all cleaned up 👼

thanks rob 🙂

y’all have fun now - merry conjmas!

xmas… x for transducers you know 😉

xform-mas? 😎

switching between advent of clojure in the morning and python for my actual job is messing with my brain

it’s a nerd snipe

Nice solution @mikelis.vindavs

https://github.com/bhauman/advent-of-clojure-2016/blob/master/src/advent_of_clojure_2017/day15.clj

just went for the straightforward approach today nothing special

@bhauman still cool!

https://github.com/mfikes/advent-of-code/blob/master/src/advent_2017/day_15.cljc

I messed around with macros to get it down to around 236 ms for part 1 and 675 ms for part 2.

Ahh cool. I forgot about unchecked-math and boxing. Fixing that results in 165 ms for part 1 and 295 ms for part 2.

Very cool Mike!

Good idea to use macros for inlining.

@mfikes Am I right that the macro approach only helps for inlining var values, but otherwise doesn’t help very much?