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day15: priority queue, <10 sec

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master
Clyne 3 years ago
parent 9d83aa4f3c
commit fa34a065ee
2 changed files with 41 additions and 68 deletions
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42
day15/part1.clj
Unescape Escape View File

@ -1,5 +1,3 @@
(require '[clojure.core.reducers :as r])
(def input (->> (slurp "./in") (def input (->> (slurp "./in")
(clojure.string/split-lines) (clojure.string/split-lines)
(mapv (partial mapv (comp read-string str))) (mapv (partial mapv (comp read-string str)))
@ -7,38 +5,26 @@
{[y x] (get-in % [y x])})) {[y x] (get-in % [y x])}))
(into {}))) (into {})))
(defn min-distance [dist Q] (def dim (apply max (map first (keys input))))
(r/fold
(r/monoid
#(if (< (first %1) (first %2)) %1 %2)
(constantly [##Inf []]))
(r/monoid
#(if (< (first %1) (dist %2)) %1 [(dist %2) %2])
(constantly [##Inf []]))
(r/filter
(partial contains? dist)
(apply vector Q))))
(defn find-neighbors [Q u] (defn find-neighbors [u]
(filter #(contains? Q %) [(update u 0 inc) (filter #(contains? input %) [(update u 0 inc)
(update u 0 dec) (update u 0 dec)
(update u 1 inc) (update u 1 inc)
(update u 1 dec)])) (update u 1 dec)]))
(let [dim (apply max (map first (keys input)))] (loop [dist (zipmap (keys input) (repeat ##Inf))
(loop [Q (apply sorted-set (keys input)) Q {[0 0] 0}]
dist (assoc (hash-map) [0 0] 0)]
(when (= 0 (rem (count Q) 500)) (println (count Q)))
(if (empty? Q) (if (empty? Q)
(println (dist [dim dim])) (println (dist [dim dim]))
(let [[u vu] (min-distance dist Q)] (let [[u distu] (first Q)
(recur NN (reduce
(disj Q vu) #(let [dv (+ distu (input %2))]
(reduce
#(let [alt (+ u (input %2))]
(cond-> %1 (cond-> %1
(or (not (contains? dist %2)) (< alt (dist %2))) (> ((first %1) %2) dv)
(assoc %2 alt))) (-> (update 0 assoc %2 dv)
dist (update 1 assoc %2 dv))))
(find-neighbors Q vu))))))) [dist {}]
(find-neighbors u))]
(recur (first NN) (sort-by val < (into (rest Q) (second NN)))))))

43
day15/part2.clj
Unescape Escape View File

@ -1,5 +1,3 @@
(require '[clojure.core.reducers :as r])
(def input (->> (slurp "./in") (def input (->> (slurp "./in")
(clojure.string/split-lines) (clojure.string/split-lines)
(mapv (partial mapv (comp read-string str))) (mapv (partial mapv (comp read-string str)))
@ -18,37 +16,26 @@
(into {}) (into {})
)) ))
(defn min-distance [dist Q] (def dim (apply max (map first (keys input))))
(r/fold
(r/monoid
#(if (< (first %1) (first %2)) %1 %2)
(constantly [##Inf []]))
(r/monoid
#(if (< (first %1) (dist %2)) %1 [(dist %2) %2])
(constantly [##Inf []]))
(r/filter
(partial contains? dist)
(apply vector Q))))
(defn find-neighbors [Q u] (defn find-neighbors [u]
(filter #(contains? Q %) [(update u 0 inc) (filter #(contains? input %) [(update u 0 inc)
(update u 0 dec) (update u 0 dec)
(update u 1 inc) (update u 1 inc)
(update u 1 dec)])) (update u 1 dec)]))
(let [dim (apply max (map first (keys input)))] (loop [dist (zipmap (keys input) (repeat ##Inf))
(loop [Q (apply sorted-set (keys input)) Q {[0 0] 0}]
dist (assoc (hash-map) [0 0] 0)]
(when (= 0 (rem (count Q) 500)) (println (count Q)))
(if (empty? Q) (if (empty? Q)
(println (dist [dim dim])) (println (dist [dim dim]))
(let [[u vu] (min-distance dist Q)] (let [[u distu] (first Q)
(recur NN (reduce
(disj Q vu) #(let [dv (+ distu (input %2))]
(reduce
#(let [alt (+ u (input %2))]
(cond-> %1 (cond-> %1
(or (not (contains? dist %2)) (< alt (dist %2))) (> ((first %1) %2) dv)
(assoc %2 alt))) (-> (update 0 assoc %2 dv)
dist (update 1 assoc %2 dv))))
(find-neighbors Q vu))))))) [dist {}]
(find-neighbors u))]
(recur (first NN) (sort-by val < (into (rest Q) (second NN)))))))

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