From 574d0888ccc1a27fb062ac5b09fcac4beb80e84e Mon Sep 17 00:00:00 2001
From: Adam Jeniski <adam.jeniski@flashtalking.com>
Date: Fri, 1 Dec 2023 01:13:26 -0500
Subject: [PATCH] clean up regex. compute not hardcode

---
 2023/src/day01.clj | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/2023/src/day01.clj b/2023/src/day01.clj
index 18a8452..521722a 100644
--- a/2023/src/day01.clj
+++ b/2023/src/day01.clj
@@ -6,14 +6,14 @@
 (def input (get-puzzle-input 1))
 
 (def numeric-value-map {"one" 1
-            "two" 2
-            "three" 3
-            "four" 4
-            "five" 5
-            "six" 6
-            "seven" 7
-            "eight" 8
-            "nine" 9})
+                        "two" 2
+                        "three" 3
+                        "four" 4
+                        "five" 5
+                        "six" 6
+                        "seven" 7
+                        "eight" 8
+                        "nine" 9})
 
 (defn numeric-value [s]
   (or (numeric-value-map s) s))
@@ -28,10 +28,18 @@
      (reduce +))
 
 ;; part 2
+(def forawrd-search-regex (->> (conj (keys numeric-value-map) "\\d")
+                               (string/join "|")
+                               re-pattern))
+
+(def backwards-search-regex (->> (conj (->> numeric-value-map keys (map string/reverse)) "\\d")
+                                                  (string/join "|")
+                                                  re-pattern))
+
 (->> input
      (map (fn [line]
-            (let [f (re-find #"one|two|three|four|five|six|seven|eight|nine|\d" line)
-                  l (string/reverse (re-find #"eno|owt|eerht|ruof|evif|xis|neves|thgie|enin|\d" (string/reverse line)))]
+            (let [f (re-find forawrd-search-regex line)
+                  l (string/reverse (re-find backwards-search-regex (string/reverse line)))]
               (str (numeric-value f) (numeric-value l)))))
      (map #(Integer/parseInt %))
      (reduce +))