http://adventofcode.com/2017

gistfile1.txt

;;;;;;;;;;; day 01 ;;;;;;;;;;;;;;;

;; half 1 of day 01

;; init sequence
(def captcha "823936645345581272695677318513459491834641129844393742672553544439126314399846773234845535593355348931499496184839582118817689171948635864427852215325421433717458975771369522138766248225963242168658975326354785415252974294317138511141826226866364555761117178764543435899886711426319675443679829181257496966219435831621565519667989898725836639626681645821714861443141893427672384716732765884844772433374798185955741311116365899659833634237938878181367317218635539667357364295754744829595842962773524584225427969467467611641591834876769829719248136613147351298534885563144114336211961674392912181735773851634298227454157885241769156811787611897349965331474217223461176896643242975397227859696554492996937235423272549348349528559432214521551656971136859972232854126262349381254424597348874447736545722261957871275935756764184378994167427983811716675476257858556464755677478725146588747147857375293675711575747132471727933773512571368467386151966568598964631331428869762151853634362356935751298121849281442128796517663482391226174256395515166361514442624944181255952124524815268864131969151433888721213595267927325759562132732586252438456569556992685896517565257787464673718221817783929691626876446423134331749327322367571432532857235214364221471769481667118117729326429556357572421333798517168997863151927281418238491791975399357393494751913155219862399959646993428921878798119215675548847845477994836744929918954159722827194721564121532315459611433157384994543332773796862165243183378464731546787498174844781781139571984272235872866886275879944921329959736315296733981313643956576956851762149275521949177991988236529475373595217665112434727744235789852852765675189342753695377219374791548554786671473733124951946779531847479755363363288448281622183736545494372344785112312749694167483996738384351293899149136857728545977442763489799693492319549773328626918874718387697878235744154491677922317518952687439655962477734559232755624943644966227973617788182213621899579391324399386146423427262874437992579573858589183571854577861459758534348533553925167947139351819511798829977371215856637215221838924612644785498936263849489519896548811254628976642391428413984281758771868781714266261781359762798")

;;convert to vector of longs
(def v (mapv #(Long/parseLong %) (map str captcha)))

;; partition vector by pairs with step 1. and add last and first digits as pair to it.
(defn make-pairs
  [v]
  (conj (into [] (partition 2 1 v)) (list (last v) (first v))))

(defn find-matched  
  [result pair]
  (if (= (first pair)
         (second pair))
    (conj result (first pair))
    result))

(def day01-answer-1 (reduce + (reduce find-matched [] (make-pairs v) )))

;; half 2 of day 01

(defn get-half-len-element [v idx]
  (let [half-len (/ (count v) 2)] 
    (first (drop half-len (drop idx (cycle v))))))

(def half-v (for [i (range (count v))
                  :let [x (nth v i)
                        y (get-half-len-element v i)]
                  :when (= x y)]
              x))

(def day01-answer-2 (reduce + half-v))

;;;;;;;;;;; day 02 ;;;;;;;;;;;;;;;

(def init-matrix [[737	1866	1565	1452	1908	1874	232	1928	201	241	922	281	1651	1740	1012	1001]
                  [339	581	41	127	331	133	51	131	129	95	499	527	518	435	508	494]
                  [1014	575	1166	259	152	631	1152	1010	182	943	163	158	1037	1108	1092	887]
                  [56	491	409	1263	1535	41	1431	1207	1393	700	1133	53	131	466	202	62]
                  [632	403	118	352	253	672	711	135	116	665	724	780	159	133	90	100]
                  [1580	85	1786	1613	1479	100	94	1856	546	76	1687	1769	1284	1422	1909	1548]
                  [479	356	122	372	786	1853	979	116	530	123	1751	887	109	1997	160	1960]
                  [446	771	72	728	109	369	300	746	86	910	566	792	616	84	338	57]
                  [6599	2182	200	2097	4146	7155	7018	1815	1173	4695	201	7808	242	3627	222	7266]
                  [1729	600	651	165	1780	2160	626	1215	149	179	1937	1423	156	129	634	458]
                  [1378	121	146	437	1925	2692	130	557	2374	2538	2920	2791	156	317	139	541]
                  [1631	176	1947	259	2014	153	268	752	2255	347	227	2270	2278	544	2379	349]
                  [184	314	178	242	145	410	257	342	183	106	302	320	288	151	449	127]
                  [175	5396	1852	4565	4775	665	4227	171	4887	181	2098	4408	2211	3884	2482	158]
                  [1717	3629	244	258	281	3635	235	4148	3723	4272	3589	4557	4334	4145	3117	4510]
                  [55	258	363	116	319	49	212	44	303	349	327	330	316	297	313	67]])

(def diffs (for [row init-matrix
                 :let [min-v (apply min row)
                       max-v (apply max row)]]
             (- max-v min-v)))

(def day02-answer-1 (reduce + diffs))

;;half 2 of day 02

(defn divisible-by?
  "return if x divisible by y without remainder."
  [x y]
  (instance? java.lang.Long (/ x y)))

(def diffs2 (for [row init-matrix
                  :let [sorted-row (into [] (sort > row)) 
                        result (loop [dividend (first sorted-row)
                                      divisors (into [] (rest sorted-row))]
                                 (when dividend
                                   (let [found-divisors (filter #(divisible-by? dividend %) divisors)]
                                     (if (not (empty? found-divisors))
                                       (/ dividend (first found-divisors))
                                       (recur (first divisors) (into [] (rest divisors)))))))]
                  :when (not (nil? result))]
              result))

(def day02-answer-2 (reduce + diffs2))

;;;;;;;;;;; day 03 ;;;;;;;;;;;;;;;

(defn square [x] (* x x))

(defn  up-corner
  "return start value if next square"
  [input ]
  (let [v (int (-> input Math/sqrt Math/ceil))]
    (if (even? v)
      (+ 1 v)
      v)))

(defn low-corner
  "return start value of current square"
  [up-corner]
  (- up-corner 2))


;; input value is always:  low-corner <= input <=up-corner

(defn detect-side-and-delta
  "detect direction and delta from start of current side of square"
  [up-corner low-corner input]
  (first (for [direction [:up :left :down :right]
               side-delta (range 1 up-corner)
               :let [cur-val (+ (square low-corner) side-delta (* (- up-corner 1) (case direction
                                                                                    :up 0
                                                                                    :left 1
                                                                                    :down 2
                                                                                    :right 3)))]
               :when (= cur-val input)]
           [direction side-delta])))


(defn manh-dist
  [input]
  (let [square-side (dec (up-corner input))
        [_ delta] (detect-side-and-delta (up-corner input) (low-corner (up-corner input)) input) 
        half-size (/ square-side 2)]
    (if (>= delta half-size)
      (+ half-size (- delta half-size))
      (+ half-size (- half-size delta)))))


(manh-dist 325489)