Clojurians Log v2

thanks for mentioning re-seq, I remember when I first encountered it and then suddenly I use it literally everywhere. Another tip: with destructuring, you get really smooth group matches to bound names: EG from my day2 of Advent:

(let [[_ lower upper letter pass] (first (re-seq #"([0-9]+)-([0-9]+) ([a-zA-Z]): (.+)" line))]
  ;; do stuff with lower, upper, letter, pass
  )

@neeasade If you use re-matches you don’t even need the first:

(let [[_ pmin pmax pc password]
      (re-matches #"(\d+)-(\d+) ([a-z]): ([a-z]+)" s)])

Good morning

Day 5 probably would have been a lot easier if I had carefully read the problem.. Not too bad though..

Day 5 done. I found the wording of part 2 to be very confusing. Lost time trying to figure out WTF was being asked for. Once I understood, the solution was pretty simple.

;; part 1
(def input (str/split-lines (slurp "resources/day05.data")))
(def fblrbits {\F 0 \B 1 \L 0 \R 1})

(defn seatcode [v]
  (-> (apply str (map fblrbits v)) (Integer/parseInt 2)))

(def codes (map seatcode input))
(apply max codes)

;; part 2
(let [dc (partition 2 1 (sort codes))]
  (inc (ffirst (filter (fn [[a b]] (= 2 (- b a))) dc))))

Agreed, the wording of part 2 took a while to interpret. I thought the description in part one was also a very long winded way to describe binary that could easily lead someone down a very long unproductive path. I suspect that was intentional and that you’re supposed to be rewarded (with time savings) for insights that lead to dramatically simpler solutions. I’m pretty happy with my 6 line solution to part 1. Part 2 took another 2 lines but is slightly hacky. Looking forward to seeing other approaches.

Definitely more verbose than the previous one 🙂. This is my post-submission cleaned-up version: https://github.com/rjray/advent-2020-clojure/blob/master/src/advent_of_code/day05bis.clj

My cat started screaming right at that time, making it very difficult to focus on the problem. 📝 memo: take the cat away for tomorrow’s puzzle.

I solved part2 before I had a correct expression to solve it, just by doing some data exploration … the solution appeared clearly in the middle of false positives.

Hi 👋 here's https://github.com/ocisly/advent2020/blob/94b52d8bb63865a8ace75f34226f6acb390c69ef/day-5.clj#L5-L36

Good morning. Probably can be done nicer using an index instead of a vector representation but it’s Saturday. I hope to see an example with index later today 🙂 https://github.com/transducer/adventofcode/blob/master/src/adventofcode/2020/day5.clj

https://github.com/nbardiuk/adventofcode/blob/master/2020/src/day05.clj spoiler 👇

seat number is just a binary with 0 and 1 replaced with L|F and R|B

another trick is how to parse it … there is a clojure function for that

Very nice

@vincent.cantin cannot find anything suitable, I am very intrigued 😮

@nbardiuk https://github.com/green-coder/advent-of-code-2020/blob/master/src/aoc/day_5.clj#L20-L21

oh cool! learn something new with every puzzle 😆

https://github.com/lambdaisland/aoc_2020/blob/main/src/lambdaisland/aoc_2020/puzzle05.clj

I guess I'm the only one who actually bothered to use bit-shift/bit-or 🙂

edn/read-string is a good parser

https://github.com/jreighley/aoc2020/blob/master/src/day5.clj. Kinda messy — I always feel clever when I can map gibberish data to functions.

@plexus I like your approach for part2

the (partition coll n 1) trick has saved me more than once

Today's video: https://youtu.be/eNMJH_GZld0

I solved it literally how it says (spoiler) 😞

(defn decode [lo hi s]
  (if-let [c (first s)]
    (case c
      (\F \L) (recur lo (+ lo (quot (- hi lo) 2)) (next s))
      (\B \R) (recur (+ lo (inc (quot (- hi lo) 2))) hi (next s)))
    lo))

full solution https://github.com/zelark/AoC-2020/blob/3cc64ff25278f82d262c4c32c2eec4268c0997a5/src/zelark/aoc_2020/day_05.clj

refactored one https://github.com/zelark/AoC-2020/blob/master/src/zelark/aoc_2020/day_05.clj

And my final decode

(defn decode [code]
  (-> (str/escape code {\F 0 \L 0 \B 1 \R 1})
      (Long/parseLong 2)))

Cool! escape another function I've learned today

Ooh that's a good one! Sequestering it for my toolbox :) 🧰

I did it even more literally. 😃 I figured while doing it that there must be another way, but the thing with gold stars is that they give me fever and make me indifferent to what happens to gnomes and kittens.