Clojurians Log v2

super far behind because of end of year work 😕

maybe i'll try to squeeze today in then fill in the past days

weird.. got day21/1 but not /2

https://github.com/minikomi/advent-of-code/blob/master/src/advent/2017/day21.clj

any easy overlooked-rule type bugs? keep getting the wrong output for part2 😕

Day 25: https://github.com/mfikes/advent-of-code/blob/master/src/advent_2017/day_25.cljc

Heheh, you actually parsed the directions from the file. 😄

I took the boring way out to start

Maybe I'll do that later 🙂

Yeah, I was tempted to just write it in code 🙂

Especially since the input was so short 🙂

Today was easy. I think the ethical thing of them to do, to have a nice Christmas day with the family 😉

Thanks all for the fun times in here the last 25 days!

Nice t-shirt: https://teespring.com/advent-of-code-eu#pid=389&cid=100029&sid=front

i skipped parsing of input today, not a part i really enjoy, and very simple to convert to a clojure structure in an editor using multicursors 🙂

i was also slightly afraid that they will come up with something terrible today

my code, nothing very clever: https://github.com/ihabunek/aoc2017/blob/master/src/aoc2017/day25.clj

@ihabunek very similar to mine 🙂 https://github.com/borkdude/aoc2017/blob/master/src/day25.clj

ah, iterate

i tend start with loop/recur and forget about iterate

how fast is yours?

mine takes a bit, ~15s

ah, i see the comment, 10s

iterate applies to a lot of solutions. 10s over here on a Macbook Pro 15" 2015

I’ve read somewhere in an article that all puzzles should run below or around 10s on 10year old hardware

yeah, saw that

but depends on the language i guess

Right, I think he means when you’re using a mutable language like Java or C

on my desktop (bash on windows, i5), your solution takes 8s, and mine takes 6s

on my laptop it takes 15ish

And we can get to that speed, @mfikes and I got to world domination on day 5: https://github.com/borkdude/aoc2017/blob/master/src/day05.clj#L115

Yes, loop recur is somewhat faster than iterate I think, because it doesn’t construct a seq

@borkdude need to examine that 🙂

@ihabunek

(time
   (loop [counter 0]
     (if (= counter 100000000)
       counter
       (recur (inc counter))))) ;; 33ms

(time (nth (iterate inc 0) 100000000)) ;; 2797 ms

right, seqs have some overhead

i learned that on one of the earlier days

Slightly faster:

(time
   (transduce
    (drop 100000000)
    (fn
      ([] nil)
      ([acc] acc)
      ([acc n]
       (reduced (or acc n))))
    (iterate inc 0))) ;; 1915ms

Mission accomplished! Thanks everybody that was fun

@borkdude in newer versions of Clojure (1.8+ IIRC) that can be done with (range) instead of (iterate). If the input args are longs there's a fastpath in Clojure that produces a reducible that stores the state as unboxed longs.

On my hardware, the transduce over iterate above takes 2071 ms in the clj REPL. With the update to iterate in ClojureScript master, in Planck this same form takes 1779 ms.

Interestingly in the node REPL the first execution takes around 750 ms, and subsequent ones drop back down to 1800 ms.

https://github.com/bhauman/advent-of-clojure-2016/blob/master/src/advent_of_clojure_2017/day25.clj

It's been super fun and educational to do this with you all! Thanks for everything!

Merry Holidays!

This is a type of project where Cljs really shines. The JS jits are much better at auto unboxing

The input arg for my typical use aren’t ints, I just need the behavior of iterate to produce successive game states