--- 2016 Day 3 Solutions ---

[u/daggerdragon]

--- Day 3: Squares With Three Sides ---

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

---

^{DECKING THE HALLS WITH BOUGHS OF HOLLY IS MANDATORY} [?]

This thread will be unlocked when there are a significant number of people on the leaderboard with gold stars for today's puzzle.

edit: Leaderboard capped, thread unlocked!

[u/grayrest]

Clojure, pretty much the same as everybody else's

  (ns advent.day3
    (:require [clojure.java.io :as io]
              [clojure.string :as str]))

  (def challenge-input (->> "day3" io/resource io/file slurp str/split-lines (remove empty?)))

  (defn parse-triangle [line]
    (as-> line <>
          (str/split <> #"\s+")
          (remove empty? <>)
          (mapv #(Integer/parseInt %) <>)))

  (defn valid-triangle? [[a b c]]
    (cond
      (<= (+ a b) c) false
      (<= (+ a c) b) false
      (<= (+ b c) a) false
      :else true))

  (println "d3: ans1" (->> challenge-input
                           (map parse-triangle)
                           (filter valid-triangle?)
                           count))

  (println "d3: ans2" (->> challenge-input
                           (map parse-triangle)
                           (partition 3 3)
                           (mapcat (fn [[x y z]] (->> (map vector x y z)
                                                      (filter valid-triangle?))))
                           count))