From efcc7c32228d87f9f41cd5963491e9d11ee30dfb Mon Sep 17 00:00:00 2001
From: Oscar Najera <hi@oscarnajera.com>
Date: Sat, 11 Feb 2023 19:34:20 +0100
Subject: Clojure day05

---
 AoC2022/05/solver.el                     | 26 +++++++++-------------
 AoC2022/aocclj/src/aocclj/day05.clj      | 38 ++++++++++++++++++++++++++++++++
 AoC2022/aocclj/test/aocclj/core_test.clj |  7 ++++++
 3 files changed, 55 insertions(+), 16 deletions(-)
 create mode 100644 AoC2022/aocclj/src/aocclj/day05.clj

diff --git a/AoC2022/05/solver.el b/AoC2022/05/solver.el
index ed42bb2..b81e4be 100644
--- a/AoC2022/05/solver.el
+++ b/AoC2022/05/solver.el
@@ -15,6 +15,7 @@
 ;;
 ;;; Code:
 (require 'subr-x)
+(require 'cl-lib)
 
 (defun solver-build-stacks ()
   (let* ((stacks-len (length
@@ -27,38 +28,31 @@
             (aref stacks (/ (- next (line-beginning-position) 1) 4))))
     stacks))
 
-(defun solver-single-move! (stacks amount from to)
-  (dotimes (_ amount)
-    (push (pop (aref stacks from)) (aref stacks to))))
-
-(defun solver-bulk-move! (stacks amount from to)
-  (setf (aref stacks to)
-        (append (seq-take (aref stacks from) amount)
-                (aref stacks to)))
-  (setf (aref stacks from) (seq-drop (aref stacks from) amount)))
-
-(defun solver-apply-moves (execution stacks)
+(defun solver-apply-moves! (mover-f stacks)
   (while (re-search-forward (rx bol "move " (group (+ digit)) " from " (group (+ digit)) " to " (group (+ digit))) nil t)
     (let ((amount (string-to-number (match-string 1)))
           (from (1- (string-to-number (match-string 2))))
           (to (1- (string-to-number (match-string 3)))))
-      (funcall execution stacks amount from to)))
+      (setf (aref stacks to)
+            (append (funcall mover-f (seq-take (aref stacks from) amount))
+                    (aref stacks to)))
+      (setf (aref stacks from) (seq-drop (aref stacks from) amount))))
   stacks)
 
-(defun solver (execution)
+(defun solver (bulkp)
   (with-temp-buffer
     (insert-file-contents "input")
     (re-search-forward "^ 1")
     (thread-last
       (solver-build-stacks)
-      (solver-apply-moves execution)
+      (solver-apply-moves! (if bulkp #'identity #'reverse))
       (cl-map 'string #'car))))
 
 (ert-deftest solver-solutions ()
   (should (equal "TPGVQPFDH"
-                 (solver #'solver-single-move!)))
+                 (solver nil)))
   (should (equal "DMRDFRHHH"
-                 (solver #'solver-bulk-move!))))
+                 (solver t))))
 
 
 (provide 'solver)
diff --git a/AoC2022/aocclj/src/aocclj/day05.clj b/AoC2022/aocclj/src/aocclj/day05.clj
new file mode 100644
index 0000000..09317a8
--- /dev/null
+++ b/AoC2022/aocclj/src/aocclj/day05.clj
@@ -0,0 +1,38 @@
+(ns aocclj.day05
+  (:require [clojure.string :as str]))
+
+(defn parse-instruction [line]
+  (->> (re-seq #"\d+" line)
+       (map parse-long)
+       (apply (fn [move from to]
+                [move (dec from) (dec to)]))))
+
+(defn parse-input [input]
+  (let [[stacks instructions] (str/split input #"\n\n")]
+    {:stacks
+     (mapv
+      (fn [col] (filter #(not= % \space) col))
+      (apply mapv vector
+             (map (comp (partial map second)
+                        (partial partition-all 4))
+                  (butlast (str/split-lines stacks)))))
+     :instructions
+     (map parse-instruction (str/split-lines instructions))}))
+
+(defn mover [f stacks [amount from to]]
+  (let [stuff (f (take amount (get stacks from)))]
+    (-> stacks
+        (update to #(apply conj % stuff))
+        (update from (partial drop amount)))))
+
+(defn solver [single? input]
+  (let [{:keys [stacks instructions]}
+        (parse-input input)]
+    (->>
+     (reduce
+      (partial mover (if single? identity reverse))
+      stacks
+      instructions)
+     (map first)
+     (apply str))))
+
diff --git a/AoC2022/aocclj/test/aocclj/core_test.clj b/AoC2022/aocclj/test/aocclj/core_test.clj
index c42285f..38e4f72 100644
--- a/AoC2022/aocclj/test/aocclj/core_test.clj
+++ b/AoC2022/aocclj/test/aocclj/core_test.clj
@@ -4,6 +4,7 @@
             [aocclj.day02 :as day02]
             [aocclj.day03 :as day03]
             [aocclj.day04 :as day04]
+            [aocclj.day05 :as day05]
             [aocclj.core :refer :all]
             [clojure.string :as str]))
 
@@ -30,3 +31,9 @@
     (are [expected function] (= expected (day04/solver function input))
       515 day04/subcontained
       883 day04/overlap)))
+
+(deftest day05
+  (let [input (slurp "../05/input")]
+    (are [expected single] (= expected (day05/solver single input))
+      "TPGVQPFDH" true
+      "DMRDFRHHH" false)))
-- 
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