You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
96 lines
3.1 KiB
Clojure
96 lines
3.1 KiB
Clojure
3 years ago
|
(require '[clojure.core.reducers :as r])
|
||
|
|
(require '[clojure.set :as set])
|
||
|
|
(require '[clojure.zip :as z])
|
||
|
|
|
||
|
|
(defn zip-depth [loc]
|
||
|
|
(loop [l loc d 0] (if (nil? l) d (recur (z/up l) (inc d)))))
|
||
|
|
|
||
|
|
(defn zip-prev-num [loc]
|
||
|
|
(loop [l loc]
|
||
|
|
(if-let [prev (z/prev l)]
|
||
|
|
(if (not (z/branch? prev))
|
||
|
|
prev
|
||
|
|
(recur prev)))))
|
||
|
|
|
||
|
|
(defn zip-next-num [loc]
|
||
|
|
(loop [l loc]
|
||
|
|
(if-let [nxt (z/next l)]
|
||
|
|
(if (not (z/branch? nxt))
|
||
|
|
(when (some? (z/node nxt)) nxt)
|
||
|
|
(recur nxt)))))
|
||
|
|
|
||
|
|
(defn snailfish-explode [tree]
|
||
|
|
(loop [node (z/vector-zip tree)]
|
||
|
|
(if (z/end? node)
|
||
|
|
node
|
||
|
|
(if (and (z/branch? node)
|
||
|
|
(= 2 (count (z/children node)))
|
||
|
|
(and (not (z/branch? (z/down node))) (not (z/branch? (z/next (z/down node)))))
|
||
|
|
(> (zip-depth node) 5))
|
||
|
|
(let [children (z/children node)
|
||
|
|
nnode (z/replace node 0)]
|
||
|
|
(if-let [prev (zip-prev-num nnode)]
|
||
|
|
(z/root
|
||
|
|
(let [new-prev (z/edit prev + (first children))]
|
||
|
|
(if-let [nxt (nth (iterate zip-next-num new-prev) 2)]
|
||
|
|
(z/edit nxt + (second children))
|
||
|
|
new-prev)))
|
||
|
|
(when-let [nxt (zip-next-num nnode)]
|
||
|
|
(z/root (z/edit nxt + (second children))))))
|
||
|
|
(recur (z/next node))))))
|
||
|
|
|
||
|
|
(defn snailfish-split [tree]
|
||
|
|
(loop [node (z/vector-zip tree)]
|
||
|
|
(if (or (z/end? node) (nil? (z/node node)))
|
||
|
|
node
|
||
|
|
(if (and (not (z/branch? node)) (> (z/node node) 9))
|
||
|
|
(z/root
|
||
|
|
(z/replace node
|
||
|
|
(z/make-node node (z/node node)
|
||
|
|
(map long [(Math/floor (/ (z/node node) 2))
|
||
|
|
(Math/ceil (/ (z/node node) 2))]))))
|
||
|
|
(recur (z/next node))))))
|
||
|
|
|
||
|
|
(defn snailfish-magnitude [ntree]
|
||
|
|
(if (= 2 (count (z/children ntree)))
|
||
|
|
(let [cl (z/down ntree) cr (z/right cl)]
|
||
|
|
(+ (* 3 (if (z/branch? cl) (snailfish-magnitude cl) (z/node cl)))
|
||
|
|
(* 2 (if (z/branch? cr) (snailfish-magnitude cr) (z/node cr)))))
|
||
|
|
(loop [node (z/down ntree) sum 0]
|
||
|
|
(if (nil? node)
|
||
|
|
sum
|
||
|
|
(recur (z/right node)
|
||
|
|
(+ sum (if (z/branch? node) (snailfish-magnitude node) (z/node node))))))))
|
||
|
|
|
||
|
|
(defn snailfish-solve [add-list]
|
||
|
|
(snailfish-magnitude
|
||
|
|
(loop [result (z/vector-zip (vec (take 2 add-list)))
|
||
|
|
next-input (drop 2 add-list)]
|
||
|
|
(let [explode (snailfish-explode result)]
|
||
|
|
(if (nil? (second explode))
|
||
|
|
(recur explode next-input)
|
||
|
|
(let [splt (snailfish-split result)]
|
||
|
|
(if (nil? (second splt))
|
||
|
|
(recur splt next-input)
|
||
|
|
(if (empty? next-input)
|
||
|
|
result
|
||
|
|
(recur (z/vector-zip
|
||
|
|
[(vec (z/children result)) (first next-input)])
|
||
|
|
(rest next-input))))))))))
|
||
|
|
|
||
|
|
; Build input list
|
||
|
|
(def input (->> (slurp "./in")
|
||
|
|
clojure.string/split-lines
|
||
|
|
(map read-string)))
|
||
|
|
|
||
|
|
; Part 1
|
||
|
|
(println (snailfish-solve input))
|
||
|
|
|
||
|
|
; Part 2
|
||
|
3 years ago
|
(->> (for [in input in2 input :when (not= in in2)] [in in2])
|
||
|
|
(vec)
|
||
|
3 years ago
|
(r/map snailfish-solve)
|
||
|
|
(r/fold (r/monoid max (constantly 0)))
|
||
|
|
(println))
|
||
|
|
|