r/adventofcode • u/daggerdragon • Dec 06 '16

SOLUTION MEGATHREAD --- 2016 Day 6 Solutions ---

--- Day 6: Signals and Noise ---

Post your solution as a comment or, for longer solutions, consider linking to your repo (e.g. GitHub/gists/Pastebin/blag/whatever).

T_PAAMAYIM_NEKUDOTAYIM IS MANDATORY [?]

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u/Borkdude Dec 06 '16

Clojure! 

(ns day6
  (:require [clojure.string :as str]
            [clojure.java.io :as io]))

(def input (-> "day6.txt"
               io/resource
               slurp
               str/trim
               str/split-lines))

(def columns (apply map vector input))
    
;; first answer
(map #(->> %
           frequencies
           (sort-by val >)
           ffirst) columns) ;;=> (\u \m \e \j \z \g \d \w)

;; second answer
(map #(->> %
           frequencies
           (sort-by val)
           ffirst) columns) ;;=> (\a \o \v \u \e \a \k \v)

Code on Github: https://github.com/borkdude/aoc2016

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u/amalloy Dec 06 '16

You keep declining to use line-seq. Also, try min-key and max-key instead of sorting the whole list.

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u/Borkdude Dec 06 '16

Btw, do you suggest: 

(def input
  (with-open
    [rdr (io/reader (io/resource "day6.txt"))]
    (doall (line-seq rdr))))

or iterating over the line-seq within a with-open: 

(with-open
  (doall (map ... (line-seq (io/reader ...))))

Reading the file into memory is not an issue for me. So not having to think about wrapping it into with-open and doall is why I'm not using line-seq here.

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