day 1, part 2

src/day01.clj

@@ -1,7 +1,7 @@
 (ns day01
   (:require [clojure.string :as string]))
 
-(def input (-> "inputs/day01.test.1"
+(def input (-> "inputs/day01"
                slurp
                (string/split #"\n")))
 
@@ -20,11 +20,7 @@
 
 ;; part two
 
-(def input2 (-> "inputs/day01.test.2"
-               slurp
-               (string/split #"\n")))
-
-(def replace-digits
+(def replacements
   {"one" "1"
    "two" "2"
    "three" "3"
@@ -35,15 +31,29 @@
    "eight" "8"
    "nine" "9"})
 
-(defn fix-line [l]
-  (let [replacements (->> (keys replace-digits)
-                          (mapcat (fn [d] {d (string/index-of l d)}))
-                          (filter (fn [[_ v]] (not (nil? v))))
-                          (sort-by second))
-        fix-fn (apply comp
-                      (map (fn [[r _]] (fn [s] (string/replace s r (replace-digits r))))
-                           replacements))]
-    (fix-fn l)))
+(defn replace-digit [d]
+  (if-let [d' (replacements d)]
+    d' d))
+
+(defn find-indices [s d]
+  (loop [is []
+         i (string/index-of s d)]
+    (if (nil? i)
+      is
+      (recur (conj is i)
+             (string/index-of s d (inc i))))))
+
+(defn actual-calibration-value [s]
+  (let [indexed-digits
+        (->> (mapcat seq replacements)
+             (mapcat (fn [d] {d (find-indices s (str d))}))
+             (remove (fn [[_ is]] (empty? is)))
+             (mapcat (fn [[d is]] (zipmap is (repeat d))))
+             (sort-by key))
+        f (val (first indexed-digits))
+        l (val (last indexed-digits))]
+    (read-string (str (replace-digit f)
+                      (replace-digit l)))))
 
 (def sum-of-actual-calibration-values
-  (reduce + (map (comp calibration-value fix-line) input2)))
+  (reduce + (map actual-calibration-value input)))