Day 2

2023-12-03 17:11:15 +00:00
parent 1f505a7cce
commit a48aaa78b1
4 changed files with 109 additions and 0 deletions
--- a/AdventOfCode2023.FSharp/AdventOfCode2023.FSharp.Lib/Day2.fs
+++ b/AdventOfCode2023.FSharp/AdventOfCode2023.FSharp.Lib/Day2.fs
@@ -0,0 +1,61 @@
+namespace AdventOfCode2023
+
+open System
+
+[<RequireQualifiedAccess>]
+module Day2 =
+
+    let part1 (s : string) =
+        use lines = StringSplitEnumerator.make '\n' s
+        let mutable answer = 0
+
+        for line in lines do
+            if not line.IsEmpty then
+                use mutable words = StringSplitEnumerator.make' ' ' line
+                let mutable prevWord = ReadOnlySpan<char>.Empty
+                let mutable isOk = true
+
+                while isOk && words.MoveNext () do
+                    match words.Current.[0] with
+                    | 'b' ->
+                        if Int32.Parse prevWord > 14 then
+                            isOk <- false
+                    | 'r' ->
+                        if Int32.Parse prevWord > 12 then
+                            isOk <- false
+                    | 'g' ->
+                        if Int32.Parse prevWord > 13 then
+                            isOk <- false
+                    | _ -> ()
+
+                    prevWord <- words.Current
+
+                if isOk then
+                    answer <- answer + Int32.Parse (line.Slice (5, line.IndexOf ':' - 5))
+
+        answer
+
+    let part2 (s : string) =
+        use lines = StringSplitEnumerator.make '\n' s
+        let mutable answer = 0
+
+        for line in lines do
+            if not line.IsEmpty then
+                let mutable reds = 0
+                let mutable blues = 0
+                let mutable greens = 0
+                use mutable words = StringSplitEnumerator.make' ' ' line
+                let mutable prevWord = ReadOnlySpan<char>.Empty
+
+                while words.MoveNext () do
+                    match words.Current.[0] with
+                    | 'b' -> blues <- max blues (Int32.Parse prevWord)
+                    | 'r' -> reds <- max reds (Int32.Parse prevWord)
+                    | 'g' -> greens <- max greens (Int32.Parse prevWord)
+                    | _ -> ()
+
+                    prevWord <- words.Current
+
+                answer <- answer + (reds * greens * blues)
+
+        answer