From 9d90dd828eb50a3f56ffcc9e1305dcb85d4b0f91 Mon Sep 17 00:00:00 2001
From: Steve Dunham <dunhamsteve@gmail.com>
Date: Tue, 24 Dec 2024 22:28:46 -0800
Subject: [PATCH] day25

---
 aoc2024/Day25.newt                    | 68 +++++++++++++++++++++++++++
 aoc2024/day25/eg.txt                  | 39 +++++++++++++++
 playground/samples/aoc2024/Day25.newt |  1 +
 playground/samples/aoc2024/day25      |  1 +
 4 files changed, 109 insertions(+)
 create mode 100644 aoc2024/Day25.newt
 create mode 100644 aoc2024/day25/eg.txt
 create mode 120000 playground/samples/aoc2024/Day25.newt
 create mode 120000 playground/samples/aoc2024/day25

diff --git a/aoc2024/Day25.newt b/aoc2024/Day25.newt
new file mode 100644
index 0000000..e180978
--- /dev/null
+++ b/aoc2024/Day25.newt
@@ -0,0 +1,68 @@
+module Day25
+
+import Prelude
+import Node
+import Aoc
+
+data Chunk : U where
+  Key : List Int → Chunk
+  Lock : List Int → Chunk
+
+-- cribbed from the idris library, it's late and I don't want to work thisout
+transpose : ∀ a. List (List a) → List (List a)
+transpose Nil = Nil
+transpose {a} (heads :: tails) = spreadHeads heads (transpose tails)
+  where
+    spreadHeads : List a → List (List a) → List (List a)
+    spreadHeads Nil tails = tails
+    spreadHeads (head :: heads) Nil = (head :: Nil) :: spreadHeads heads Nil
+    spreadHeads (head :: heads) (tail :: tails) = (head :: tail) :: spreadHeads heads tails
+
+count : List Char → Int
+count cs = go cs 0
+  where
+    go : List Char → Int → Int
+    go ('#' :: cs) acc = go cs (1 + acc)
+    go _ acc = acc
+
+toChunk : List (List Char) → Chunk
+
+parseChunk : String → Chunk
+parseChunk text =
+  let stuff = transpose $ map unpack $ split text "\n" in
+  -- TODO - sort this out
+  case map {List} count stuff of
+    0 :: xs => Key $ map (count ∘ reverse) stuff
+    xs => Lock xs
+
+
+parseFile : String → List Chunk
+parseFile text = do
+  let parts = split (trim text) "\n\n"
+  map parseChunk parts
+
+splitKeys : List Chunk → List (List Int) → List (List Int) → List (List Int) × List (List Int)
+splitKeys (Lock xs :: rest) locks keys = splitKeys rest (xs :: locks) keys
+splitKeys (Key xs :: rest) locks keys = splitKeys rest locks (xs :: keys)
+splitKeys Nil locks keys = (locks, keys)
+
+check : List Int → List Int → Int
+check Nil Nil = 1
+check (a :: as) (b :: bs) = if a + b <= 7 then check as bs else 0
+check _ _ = 0
+
+run : String -> IO Unit
+run fn = do
+  putStrLn fn
+  text <- readFile fn
+  putStrLn text
+  let chunks = parseFile text
+  let (locks,keys) = splitKeys chunks Nil Nil
+  debugLog (length locks, length keys)
+  let p1 = foldl _+_ 0 $ map (\ l => foldl _+_ 0 $ map (check l) keys) locks
+  putStrLn $ "part1 " ++ show p1
+
+main : IO Unit
+main = do
+  run "aoc2024/day25/eg.txt"
+  run "aoc2024/day25/input.txt"
diff --git a/aoc2024/day25/eg.txt b/aoc2024/day25/eg.txt
new file mode 100644
index 0000000..8e29855
--- /dev/null
+++ b/aoc2024/day25/eg.txt
@@ -0,0 +1,39 @@
+#####
+.####
+.####
+.####
+.#.#.
+.#...
+.....
+
+#####
+##.##
+.#.##
+...##
+...#.
+...#.
+.....
+
+.....
+#....
+#....
+#...#
+#.#.#
+#.###
+#####
+
+.....
+.....
+#.#..
+###..
+###.#
+###.#
+#####
+
+.....
+.....
+.....
+#....
+#.#..
+#.#.#
+#####
diff --git a/playground/samples/aoc2024/Day25.newt b/playground/samples/aoc2024/Day25.newt
new file mode 120000
index 0000000..022657f
--- /dev/null
+++ b/playground/samples/aoc2024/Day25.newt
@@ -0,0 +1 @@
+../../../aoc2024/Day25.newt
\ No newline at end of file
diff --git a/playground/samples/aoc2024/day25 b/playground/samples/aoc2024/day25
new file mode 120000
index 0000000..3fda4ae
--- /dev/null
+++ b/playground/samples/aoc2024/day25
@@ -0,0 +1 @@
+../../../aoc2024/day25
\ No newline at end of file