Advent of Code, 2024 - Day 2 Part 2

.vscode/settings.json

@@ -13,6 +13,7 @@
     "HLINT",
     "mempty",
     "Prec",
+    "succ",
     "unrecognised"
   ]
 }

src/advent_of_code/2024/2.hs

@@ -33,7 +33,8 @@ solveP1 = length . filter (== True) . map safeReportP1
 solveP2 :: [[Int]] -> Int
 solveP2 = length . filter (== True) . map safeReportP2
 
-
+safeReportP1 :: [Int] -> Bool
+safeReportP1 report = isSorted report && adjacentLevelCheck report
 
 isSorted :: [Int] -> Bool
 isSorted report = report `elem` [sort report, sortOn Down report]
@@ -43,17 +44,8 @@ adjacentLevelCheck report =
   all (((== True) . (\n-> n>=1 && n<=3)) . abs)
       (zipWith subtract report (tail report))
 
-removeOneBadReport :: [Int] -> [[Int]]
-removeOneBadReport lst = map (\i -> take i lst <> drop (succ i) lst) [0..(length lst)-1]
-
-
-
-safeReportP1 :: [Int] -> Bool
-safeReportP1 report = isSorted report && adjacentLevelCheck report
-
 safeReportP2 :: [Int] -> Bool
-safeReportP2 report =
-  or $ zipWith (&&) (map adjacentLevelCheck reports) (map isSorted reports)
-  where
-    reports = removeOneBadReport report
+safeReportP2 report = any safeReportP1 (removeOneBadReport report)
 
+removeOneBadReport :: [Int] -> [[Int]]
+removeOneBadReport lst = map (\i -> take i lst <> drop (succ i) lst) [0..length lst-1]