day_2.clj

#!/usr/bin/clojure
(ns advent-of-code.day-2)

(def s "DDDURLURURUDLDURRURULLRRDULRRLRLRURDLRRDUDRUDLRDUUDRRUDLLLURLUURLRURURLRLUDDURUULDURDRUUDLLDDDRLDUULLUDURRLUULUULDLDDULRLDLURURUULRURDULLLURLDRDULLULRRRLRLRULLULRULUUULRLLURURDLLRURRUUUDURRDLURUURDDLRRLUURLRRULURRDDRDULLLDRDDDDURURLLULDDULLRLDRLRRDLLURLRRUDDDRDLLRUDLLLLRLLRUDDLUUDRLRRRDRLRDLRRULRUUDUUDULLRLUDLLDDLLDLUDRURLULDLRDDLDRUDLDDLDDDRLLDUURRUUDLLULLRLDLUURRLLDRDLRRRRUUUURLUUUULRRUDDUDDRLDDURLRLRLLRRUDRDLRLDRRRRRRUDDURUUUUDDUDUDU
RLULUULRDDRLULRDDLRDUURLRUDDDUULUUUDDRDRRRLDUURDURDRLLLRDDRLURLDRRDLRLUURULUURDRRULRULDULDLRRDDRLDRUDUDDUDDRULURLULUDRDUDDDULRRRURLRRDLRDLDLLRLUULURLDRURRRLLURRRRRLLULRRRDDLRLDDUULDLLRDDRLLUUDRURLRULULRLRUULUUUUUDRURLURLDDUDDLRDDLDRRLDLURULUUDRDLULLURDLLLRRDRURUDDURRLURRDURURDLRUDRULUULLDRLRRDRLDDUDRDLLRURURLUDUURUULDURUDULRLRDLDURRLLDRDUDRUDDRLRURUDDLRRDLLLDULRRDRDRRRLURLDLURRDULDURUUUDURLDLRURRDRULLDDLLLRUULLLLURRRLLLDRRUDDDLURLRRRDRLRDLUUUDDRULLUULDURLDUUURUDRURUDRDLRRLDRURRLRDDLLLULUDDUULDURLRUDRDDD
RDDRUDLRLDDDRLRRLRRLUULDRLRUUURULRRLUURLLLRLULDDLDLRLULULUUDDDRLLLUDLLRUDURUDDLLDUDLURRULLRDLDURULRLDRLDLDRDDRUDRUULLLLRULULLLDDDULUUDUUDDLDRLRRDLRLURRLLDRLDLDLULRLRDLDLRLUULLDLULRRRDDRUULDUDLUUUUDUDRLUURDURRULLDRURUDURDUULRRULUULULRLDRLRLLRRRLULURLUDULLDRLDRDRULLUUUDLDUUUDLRDULRDDDDDDDDLLRDULLUDRDDRURUDDLURRUULUURURDUDLLRRRRDUDLURLLURURLRDLDUUDRURULRDURDLDRUDLRRLDLDULRRUDRDUUDRLURUURLDLUDLLRDDRDU
LLDDDDLUDLLDUDURRURLLLLRLRRLDULLURULDULDLDLLDRRDLUDRULLRUUURDRLLURDDLLUDDLRLLRDDLULRLDDRURLUDRDULLRUDDLUURULUUURURLRULRLDLDDLRDLDLLRUURDLUDRRRDDRDRLLUDDRLDRLLLRULRDLLRLRRDDLDRDDDUDUDLUULDLDUDDLRLDUULRULDLDULDDRRLUUURUUUDLRDRULDRRLLURRRDUDULDUDUDULLULLULULURLLRRLDULDULDLRDDRRLRDRLDRLUDLLLUULLRLLRLDRDDRUDDRLLDDLRULLLULRDDDLLLDRDLRULDDDLULURDULRLDRLULDDLRUDDUDLDDDUDRDRULULDDLDLRRDURLLRLLDDURRLRRULLURLRUDDLUURULULURLRUDLLLUDDURRLURLLRLLRRLDULRRUDURLLDDRLDLRRLULUULRRUURRRDULRLRLRDDRDULULUUDULLLLURULURRUDRLL
UULLULRUULUUUUDDRULLRLDDLRLDDLULURDDLULURDRULUURDLLUDDLDRLUDLLRUURRUDRLDRDDRRLLRULDLLRUUULLLDLDDULDRLRURLDRDUURLURDRUURUULURLRLRRURLDDDLLDDLDDDULRUDLURULLDDRLDLUDURLLLLLRULRRLLUDRUURLLURRLLRDRLLLRRDDDRRRDLRDRDUDDRLLRRDRLRLDDDLURUUUUULDULDRRRRLUDRLRDRUDUDDRULDULULDRUUDUULLUDULRLRRURDLDDUDDRDULLUURLDRDLDDUURULRDLUDDLDURUDRRRDUDRRDRLRLULDRDRLRLRRUDLLLDDDRURDRLRUDRRDDLDRRLRRDLUURLRDRRUDRRDLDDDLRDDLRDUUURRRUULLDDDLLRLDRRLLDDRLRRRLUDLRURULLDULLLUDLDLRLLDDRDRUDLRRDDLUU")

(def data (clojure.string/split-lines s))

(def keypad [[1 2 3]
             [4 5 6]
             [7 8 9]])

(defn plus
  [[x y] [w z]]
  [(+ x w) (+ y z)])

(defn clamp [x lo hi]
  (min hi (max lo x)))

(defn normalize
  [[x y]]
  [(clamp x 0 2) (clamp y 0 2)])

(defn char-to-diff [ch]
  (case ch
        \U [ 0 -1]
        \D [ 0  1]
        \R [ 1  0]
        \L [-1  0]))

(defn find-key [s]
  (let [[x y] (-> (fn [acc input]
                    (-> input char-to-diff (plus acc) normalize))
                  (reduce [1 1] s))]
    (get-in keypad [y x])))

(defn -main
  []
  (prn (map find-key data)))