2023 day 1

.gitignore

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+*.fasl
+data.txt

2023/1/Main.hs

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+import Data.Char (isDigit, digitToInt)
+import Data.Function (on)
+import Data.List (tails, findIndex, isPrefixOf, minimumBy)
+import Data.Maybe (mapMaybe)
+import Data.Bifunctor (first)
+
+type LineOp = String -> Int
+
+wordMap :: [(String, Int)]
+wordMap = [ ("one", 1)
+          , ("two", 2)
+          , ("three", 3)
+          , ("four", 4)
+          , ("five", 5)
+          , ("six", 6)
+          , ("seven", 7)
+          , ("eight", 8)
+          , ("nine", 9)
+          ]
+
+fullWordMap :: [(String, Int)]
+fullWordMap = wordMap ++ (zip =<< map show) [1..9]
+
+opLineBasic :: LineOp
+opLineBasic l = (combineDigits `on` ($ digitToInt <$> filter isDigit l)) head last
+
+firstNumInLine :: String -> [(String, Int)] -> Int
+firstNumInLine l = fst . minimumBy (compare `on` snd) . mapMaybe numIndex
+  where
+    numIndex (str, num) = (num,) <$> findIndex (isPrefixOf str) (tails l)
+
+opLineAdvanced :: LineOp
+opLineAdvanced l = (combineDigits `on` uncurry firstNumInLine)
+  (l, fullWordMap)
+  (reverse l, first reverse <$> fullWordMap)
+
+combineDigits :: Int -> Int -> Int
+combineDigits = (+) . (10 *)
+
+opLines :: [String] -> Int
+opLines = sum . map opLineAdvanced
+
+main :: IO ()
+main = do
+  content <- readFile "data.txt"
+  print . opLines . lines $ content

2023/1/main-1.lisp

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+(defpackage #:aoc-2023/1.1
+  (:use #:cl)
+  (:export #:main))
+
+(in-package #:aoc-2023/1.1)
+
+(defun digits-to-integer (a b)
+  (values (parse-integer (format NIL "~A~A" a b))))
+
+(defun line-value (line)
+  (digits-to-integer (find-if #'digit-char-p line)
+                     (find-if #'digit-char-p line :from-end T)))
+
+(defun main ()
+  (format T
+          "~A~%"
+          (loop :for line := (read-line T NIL)
+                :while line
+                :unless (string= line "")
+                  :sum (line-value line))))
+
+(eval-when (:execute)
+  (main))

2023/1/main-2.lisp

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+(defpackage #:aoc-2023/1.2
+  (:use #:cl)
+  (:export #:main))
+
+(in-package #:aoc-2023/1.2)
+
+(defparameter *numbers* '(("one" . 1)
+                          ("two" . 2)
+                          ("three" . 3)
+                          ("four" . 4)
+                          ("five" . 5)
+                          ("six" . 6)
+                          ("seven" . 7)
+                          ("eight" . 8)
+                          ("nine" . 9)))
+
+(defun digits-to-integer (a b)
+  (values (parse-integer (format NIL "~A~A" a b))))
+
+(defun line-value (line)
+  (let* ((first-i (position-if #'digit-char-p line))
+         (last-i (position-if #'digit-char-p line :from-end T))
+         (first-val (when first-i (aref line first-i)))
+         (last-val (when last-i (aref line last-i))))
+    (loop :for (str . num) :in *numbers*
+          :for first := (search str line)
+          :for last := (search str line :from-end T)
+          :when first
+            :do (when (or (null first-i)
+                          (< first first-i))
+                  (setf first-i first)
+                  (setf first-val num))
+                (when (or (null last-i)
+                          (> last last-i))
+                  (setf last-i last)
+                  (setf last-val num)))
+    (digits-to-integer first-val last-val)))
+
+(defun main ()
+  (format T
+          "~A~%"
+          (loop :for line := (read-line T NIL)
+                :while line
+                :unless (string= line "")
+                  :sum (line-value line))))
+
+(eval-when (:execute)
+  (main))