day15: success, part2 ~88min; trying to improve

day15/part1.clj

@@ -1,3 +1,5 @@
+(require '[clojure.core.reducers :as r])
+
 (def input (->> (slurp "./in")
                 (clojure.string/split-lines)
                 (mapv (partial mapv (comp read-string str)))
@@ -6,13 +8,16 @@
                 (into {})))
 
 (defn min-distance [dist Q]
-  (reduce
+  (r/fold
-    #(if (and (not= (dist %2) :inf)
+    (r/monoid
-           (or (= :inf (first %1))
+      #(if (< (first %1) (first %2)) %1 %2)
-               (< (dist %2) (first %1))))
+      (constantly [##Inf []]))
-         [(dist %2) %2]
+    (r/monoid
-         %1)
+      #(if (< (first %1) (dist %2)) %1 [(dist %2) %2])
-    [:inf []] Q))
+      (constantly [##Inf []]))
+    (r/filter
+      (partial contains? dist)
+      (apply vector Q))))
 
 (defn find-neighbors [Q u]
   (filter #(contains? Q %) [(update u 0 inc)
@@ -21,22 +26,19 @@
                             (update u 1 dec)]))
 
 (let [dim (apply max (map first (keys input)))]
-  (loop [Q (set (keys input))
+  (loop [Q (apply sorted-set (keys input))
-         dist (-> (zipmap Q (repeat :inf)) (update [0 0] #(do % 0)))]
+         dist (assoc (hash-map) [0 0] 0)]
+    (when (= 0 (rem (count Q) 500)) (println (count Q)))
     (if (empty? Q)
       (println (dist [dim dim]))
       (let [[u vu] (min-distance dist Q)]
         (recur
           (disj Q vu)
-          (loop [d dist f (find-neighbors Q vu)]
+          (reduce
-            (if (empty? f)
+            #(let [alt (+ u (input %2))]
-              d
+               (cond-> %1
-              (recur
+                 (or (not (contains? dist %2)) (< alt (dist %2)))
-                (let [v (first f) alt (+ u (input v))]
+                 (assoc %2 alt)))
-                  (if (or (= :inf (dist v)) (< alt (dist v)))
+            dist
-                    (assoc d v alt)
+            (find-neighbors Q vu)))))))
-                    d
-                    ))
-                (rest f)
-                ))))))))
 

day15/part2.clj

@@ -1,3 +1,5 @@
+(require '[clojure.core.reducers :as r])
+
 (def input (->> (slurp "./in")
                 (clojure.string/split-lines)
                 (mapv (partial mapv (comp read-string str)))
@@ -17,15 +19,16 @@
                 ))
 
 (defn min-distance [dist Q]
-  (reduce
+  (r/fold
-    #(if (and (not= (dist %2) :inf)
+    (r/monoid
-           (or (= :inf (first %1))
+      #(if (< (first %1) (first %2)) %1 %2)
-               (< (dist %2) (first %1))))
+      (constantly [##Inf []]))
-         [(dist %2) %2]
+    (r/monoid
-         %1)
+      #(if (< (first %1) (dist %2)) %1 [(dist %2) %2])
-    [:inf []]
+      (constantly [##Inf []]))
-    Q
+    (r/filter
-    ))
+      (partial contains? dist)
+      (apply vector Q))))
 
 (defn find-neighbors [Q u]
   (filter #(contains? Q %) [(update u 0 inc)
@@ -33,22 +36,19 @@
                             (update u 1 inc)
                             (update u 1 dec)]))
 
-(loop [Q (set (keys input))
+(let [dim (apply max (map first (keys input)))]
-       dist (-> (zipmap Q (repeat :inf)) (update [0 0] #(do % 0)))]
+  (loop [Q (apply sorted-set (keys input))
-  (if (empty? Q)
+         dist (assoc (hash-map) [0 0] 0)]
-    (println (dist [499 499]))
+    (when (= 0 (rem (count Q) 500)) (println (count Q)))
-    (let [[u vu] (min-distance dist Q)]
+    (if (empty? Q)
-      (recur
+      (println (dist [dim dim]))
-        (disj Q vu)
+      (let [[u vu] (min-distance dist Q)]
-        (loop [d dist f (find-neighbors Q vu)]
+        (recur
-          (if (empty? f)
+          (disj Q vu)
-            d
+          (reduce
-            (recur
+            #(let [alt (+ u (input %2))]
-              (let [v (first f) alt (+ u (input v))]
+               (cond-> %1
-                (if (or (= :inf (dist v)) (< alt (dist v)))
+                 (or (not (contains? dist %2)) (< alt (dist %2)))
-                  (assoc d v alt)
+                 (assoc %2 alt)))
-                  d
+            dist
-                  ))
+            (find-neighbors Q vu)))))))
-              (rest f)
-              )))))))
-