Day 2

7 files changed, 208 insertions, 3 deletions

diff --git a/Common.lean b/Common.lean
index b95bbfd..aa53152 100644
--- a/Common.lean
+++ b/Common.lean
@@ -1,3 +1,4 @@
 import Common.Helpers
 import Common.Option
 import Common.DayPart
+import Common.String
diff --git a/Common/String.lean b/Common/String.lean
new file mode 100644
index 0000000..7fe7aee
--- /dev/null
+++ b/Common/String.lean
@@ -0,0 +1,4 @@
+namespace String
+
+def splitTrim (c : Char → Bool) (s : String) : List String :=
+  String.trim <$> s.split c
diff --git a/Day1.lean b/Day1.lean
index 9f265b8..f0e9c14 100644
--- a/Day1.lean
+++ b/Day1.lean
@@ -1,6 +1,4 @@
-import Common.Helpers
-import Common.Option
-import Common.DayPart
+import Common
 
 namespace Day1
 
diff --git a/Day2.lean b/Day2.lean
new file mode 100644
index 0000000..f0eff56
--- /dev/null
+++ b/Day2.lean
@@ -0,0 +1,97 @@
+import Common
+
+structure Draw (α : Type) where
+  red : α
+  green : α
+  blue : α
+  deriving Repr
+
+structure Game where
+  id : Nat
+  draw : List $ Draw Nat
+  deriving Repr
+
+def parse (input : String) : Option $ List Game :=
+  let lines := input.splitTrim (. == '\n')
+  let lines := lines.filter (not ∘ String.isEmpty)
+  let parse_single_line : (String → Option Game):= λ (l : String) ↦ do
+    let parse_id := λ (s : String) ↦ do
+      let rest ← if s.startsWith "Game " then some (s.drop 5) else none
+      rest.toNat?
+    let parse_draw := λ (s : String) ↦ do
+      let s := s.splitTrim (· == ',')
+      let findAndRemoveTail := λ (s : String) (t : String) ↦
+        if s.endsWith t then
+          some $ String.dropRight s (t.length)
+        else
+          none
+      let update_draw_parse := λ (pd : Option (Draw (Option String))) (c : String) ↦ do
+        let old ← pd
+        let red := findAndRemoveTail c " red"
+        let green := findAndRemoveTail c " green"
+        let blue := findAndRemoveTail c " blue"
+        match red, green, blue with
+        | some red, none, none => match old.red with
+          | none => some $ {old with red := some red}
+          | some _ => none
+        | none, some green, none => match old.green with
+          | none => some $ {old with green := some green}
+          | some _ => none
+        | none, none, some blue => match old.blue with
+          | none => some $ {old with blue := some blue}
+          | some _ => none
+        | _, _, _  => none
+      let parsed_draw ← s.foldl update_draw_parse (some $ Draw.mk none none none)
+      let parsed_draw := {
+        red := String.toNat? <$> parsed_draw.red,
+        green := String.toNat? <$> parsed_draw.green,
+        blue := String.toNat? <$> parsed_draw.blue : Draw _}
+      let extractOrFail := λ (s : Option $ Option Nat) ↦ match s with
+        | none => some 0
+        | some none => none
+        | some $ some x => some x
+      let red ← extractOrFail parsed_draw.red
+      let green ← extractOrFail parsed_draw.green
+      let blue ← extractOrFail parsed_draw.blue
+      pure { red := red, blue := blue, green := green : Draw _}
+    let parse_draws := λ s ↦ List.mapM parse_draw $ s.splitTrim (· == ';')
+    let (id, draw) ← match l.splitTrim (· == ':') with
+    | [l, r] => Option.zip (parse_id l) (parse_draws r)
+    | _ => none
+    pure { id := id, draw := draw}
+  lines.mapM parse_single_line
+
+def part1 (games : List Game) : Nat :=
+  let draw_possible := λ g ↦ g.red ≤ 12 && g.green ≤ 13 && g.blue ≤ 14
+  let possible := flip List.all draw_possible
+  let possible_games := games.filter (possible ∘ Game.draw)
+  possible_games.map Game.id |> List.foldl Nat.add 0
+
+def part2 (games : List Game) : Nat :=
+  let powerOfGame := λ (g : Game) ↦
+    let minReq := λ (c : Draw Nat → Nat) ↦
+      g.draw.map c |> List.maximum? |> flip Option.getD 0
+    minReq Draw.red * minReq Draw.green * minReq Draw.blue
+  let powers := games.map powerOfGame
+  powers.foldl Nat.add 0
+
+open DayPart
+instance : Parse ⟨2, by simp⟩ (ι := List Game) where
+  parse := parse
+
+instance : Part ⟨2,_⟩ Parts.One (ι := List Game) (ρ := Nat) where
+  run := some ∘ part1
+
+instance : Part ⟨2,_⟩ Parts.Two (ι := List Game) (ρ := Nat) where
+  run := some ∘ part2
+
+def testInput : String :=
+"Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
+Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue
+Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red
+Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red
+Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green"
+
+ -- #eval part1 <$> parse testInput
+
+ -- #eval part2 <$> parse testInput
diff --git a/Main.lean b/Main.lean
index 0739d43..15b60da 100644
--- a/Main.lean
+++ b/Main.lean
@@ -1,5 +1,6 @@
 import «Common»
 import «Day1»
+import «Day2»
 
 open DayPart
 
@@ -17,6 +18,8 @@ def try_run_day_part (day : Days) (part : Parts) (data : String) : IO String :=
   match day, part with
   | ⟨1,_⟩, Parts.One => impl ⟨1,_⟩ Parts.One data
   | ⟨1,_⟩, Parts.Two => impl ⟨1,_⟩ Parts.Two data
+  | ⟨2,_⟩, Parts.One => impl ⟨2,_⟩ Parts.One data
+  | ⟨2,_⟩, Parts.Two => impl ⟨2,_⟩ Parts.Two data
   | _, _ => throw $ IO.userError "The requested combination of day/part has not been implemented yet."
 
 def main (parameters : List String): IO Unit := do
diff --git a/inputs/day2.input b/inputs/day2.input
new file mode 100644
index 0000000..145b929
--- /dev/null
+++ b/inputs/day2.input
@@ -0,0 +1,100 @@
+Game 1: 1 green, 2 red, 6 blue; 4 red, 1 green, 3 blue; 7 blue, 5 green; 6 blue, 2 red, 1 green
+Game 2: 1 green, 17 red; 1 blue, 6 red, 7 green; 2 blue, 4 red, 7 green; 1 green, 6 red, 2 blue
+Game 3: 6 red, 15 blue, 15 green; 1 green, 4 red, 12 blue; 14 blue, 9 red, 1 green; 2 red, 15 blue, 12 green
+Game 4: 8 green, 10 blue, 6 red; 20 blue, 4 red; 17 blue, 2 green, 3 red; 4 blue, 2 green, 3 red; 10 red, 3 blue, 3 green; 5 green, 14 blue, 6 red
+Game 5: 3 green, 8 blue, 2 red; 11 red, 6 green, 11 blue; 8 red, 5 blue, 2 green
+Game 6: 2 blue, 12 red, 2 green; 3 green, 2 red; 3 green, 3 blue, 10 red; 7 red, 2 blue, 4 green; 1 red, 2 blue, 5 green
+Game 7: 1 red, 8 blue, 2 green; 1 red, 2 blue, 12 green; 1 blue; 3 blue, 3 green
+Game 8: 10 green, 4 red, 4 blue; 12 green, 1 blue; 1 red, 13 green, 2 blue; 12 green, 3 blue; 9 green, 7 red
+Game 9: 1 green, 1 blue, 3 red; 3 blue, 3 red, 8 green; 6 blue, 4 red, 6 green; 2 red, 7 green; 1 red, 10 green, 13 blue; 5 red, 1 blue, 1 green
+Game 10: 9 green, 3 red, 3 blue; 12 green, 2 blue; 18 green, 1 blue; 14 green; 2 blue, 9 green, 2 red
+Game 11: 14 green; 2 green, 2 red, 11 blue; 9 blue, 3 green
+Game 12: 9 green, 3 blue, 8 red; 1 green, 2 blue, 3 red; 4 blue, 8 red, 10 green; 3 blue, 7 red, 8 green; 3 blue, 5 red, 7 green; 2 blue, 5 green
+Game 13: 6 red, 1 blue, 10 green; 7 red, 1 green; 8 red, 2 green, 1 blue
+Game 14: 2 red, 4 blue, 2 green; 2 green, 5 red, 1 blue; 1 red, 6 blue
+Game 15: 7 blue, 3 red; 13 blue, 8 red, 1 green; 1 green, 5 red, 13 blue; 8 red, 5 blue; 4 red, 3 blue, 1 green; 12 blue, 8 red, 1 green
+Game 16: 5 blue, 1 green, 2 red; 2 blue, 20 green; 4 blue, 1 red, 17 green; 10 green, 5 blue, 2 red
+Game 17: 6 red, 13 blue, 8 green; 12 blue, 7 green, 9 red; 19 blue, 5 red; 2 green, 8 red, 14 blue
+Game 18: 5 red, 2 green, 1 blue; 8 blue, 17 red, 9 green; 2 blue, 1 green; 4 blue, 10 red; 5 blue, 4 red, 6 green
+Game 19: 5 red, 12 green; 8 red, 13 green, 1 blue; 1 red, 1 green, 3 blue; 5 green, 5 red
+Game 20: 11 red, 8 blue; 9 red, 2 green, 13 blue; 2 red, 1 green, 2 blue; 1 green, 9 blue, 13 red; 3 blue, 5 red, 1 green
+Game 21: 1 red, 4 green, 11 blue; 3 green, 15 blue; 6 green, 7 red, 14 blue; 15 blue, 6 green, 10 red; 6 red, 16 blue, 2 green
+Game 22: 2 blue, 15 green, 2 red; 3 blue, 6 green, 1 red; 2 blue, 5 green, 1 red; 6 green, 2 red, 2 blue; 4 green, 2 blue; 4 blue, 1 red, 15 green
+Game 23: 2 blue, 1 green, 12 red; 5 blue, 11 red, 4 green; 12 red, 4 blue; 12 red, 2 green, 5 blue
+Game 24: 4 blue, 7 red; 3 red, 3 blue; 1 red, 4 blue; 2 green, 6 red, 6 blue; 7 red, 1 green, 2 blue; 6 red, 1 blue, 1 green
+Game 25: 5 green, 9 blue; 6 green, 7 red, 2 blue; 1 red, 3 blue, 7 green; 9 blue, 3 red; 5 green, 9 blue, 2 red
+Game 26: 6 red, 4 blue; 2 blue, 4 green; 3 green, 5 red, 5 blue; 4 green, 6 red, 3 blue; 4 green, 7 red, 4 blue
+Game 27: 15 green, 1 blue, 12 red; 12 red, 1 green; 1 red, 1 blue, 5 green; 13 green, 6 red, 1 blue; 5 red, 1 blue, 1 green; 11 red, 14 green
+Game 28: 3 blue, 2 green, 10 red; 5 blue, 2 green; 4 green, 3 blue, 11 red
+Game 29: 10 blue, 2 red; 17 green, 7 blue, 2 red; 1 blue, 8 green, 1 red; 10 green, 2 red, 3 blue
+Game 30: 10 green, 8 red, 1 blue; 4 blue, 7 green, 14 red; 2 blue, 14 red, 11 green; 1 blue, 13 green, 12 red; 5 blue, 2 red, 4 green; 4 green, 5 red
+Game 31: 4 green, 11 red, 11 blue; 3 blue, 11 red; 5 blue, 7 red, 3 green; 10 blue, 5 green, 1 red
+Game 32: 4 red, 8 blue, 1 green; 14 red, 7 blue, 4 green; 13 red, 3 blue, 9 green; 3 red, 1 green, 8 blue; 8 green, 8 red, 5 blue
+Game 33: 6 red, 10 blue, 7 green; 19 blue, 1 red; 6 green, 11 red, 11 blue; 2 green, 2 blue, 12 red; 3 red, 13 blue, 7 green; 6 green, 4 red, 2 blue
+Game 34: 3 red, 3 green, 15 blue; 7 green, 15 blue; 3 red, 2 green, 8 blue; 19 green, 18 blue
+Game 35: 2 green, 1 blue; 2 green, 2 blue, 1 red; 3 blue, 1 red, 1 green; 4 blue, 1 red
+Game 36: 1 red, 11 green; 1 green, 1 blue; 8 blue; 2 green, 3 red; 1 red
+Game 37: 4 blue, 3 red; 12 blue, 13 red; 2 red, 2 green, 8 blue
+Game 38: 8 red, 2 blue; 1 green, 2 red; 8 red, 2 green, 1 blue; 16 red, 2 green; 7 red, 2 blue, 2 green
+Game 39: 6 green, 1 blue, 5 red; 14 green, 8 blue, 6 red; 8 red, 10 blue, 1 green; 14 green, 9 red; 17 blue, 5 red; 1 blue, 7 green, 1 red
+Game 40: 4 red, 8 blue, 3 green; 13 blue, 1 red; 3 blue, 7 red, 3 green; 3 green, 8 blue, 10 red; 3 green, 20 blue, 5 red
+Game 41: 1 blue, 2 green; 11 green, 2 blue; 5 blue; 15 red, 8 green, 5 blue
+Game 42: 1 green, 12 blue, 1 red; 6 blue, 1 green, 5 red; 1 red, 11 blue, 4 green; 3 red, 17 blue, 1 green; 1 red, 11 blue; 9 blue, 6 green, 3 red
+Game 43: 16 blue, 13 green, 1 red; 17 blue, 7 red, 10 green; 13 green, 5 red, 7 blue
+Game 44: 2 blue, 4 red; 15 green, 7 red; 2 green, 1 blue; 6 red, 13 green
+Game 45: 5 green, 1 blue, 8 red; 4 red, 1 blue, 5 green; 1 green, 3 red; 1 green, 2 blue, 6 red; 4 red, 3 green, 2 blue; 2 red, 2 blue, 5 green
+Game 46: 1 green, 1 red, 6 blue; 11 blue; 1 red, 1 green, 7 blue; 8 blue; 1 green, 7 blue, 2 red
+Game 47: 7 green, 9 blue, 7 red; 11 red, 13 blue, 5 green; 12 green, 12 blue, 5 red; 4 blue, 8 green, 7 red
+Game 48: 11 green, 7 red, 2 blue; 2 blue, 10 green, 3 red; 1 blue, 2 red, 1 green; 4 green, 2 red, 7 blue; 7 red, 4 green, 2 blue
+Game 49: 1 red, 2 blue, 5 green; 2 green, 4 blue; 5 blue, 2 green, 1 red; 9 blue, 1 green; 7 blue
+Game 50: 8 green, 9 blue, 2 red; 2 green, 5 blue; 14 green, 1 red, 8 blue
+Game 51: 1 green, 2 blue; 12 blue, 1 red; 2 blue
+Game 52: 3 red, 2 blue, 2 green; 4 red, 4 green, 7 blue; 2 blue, 4 red, 1 green; 3 green; 1 red, 9 green, 7 blue
+Game 53: 9 blue, 12 red, 7 green; 8 blue, 6 green; 1 green, 8 blue, 9 red; 12 red, 6 green; 9 blue, 14 red, 10 green; 7 red, 3 green, 5 blue
+Game 54: 8 green, 5 blue, 5 red; 4 green, 13 blue, 2 red; 2 blue, 5 red, 1 green; 3 red, 3 green, 10 blue
+Game 55: 17 red, 15 green, 17 blue; 6 red, 5 green, 7 blue; 17 green, 6 blue, 5 red
+Game 56: 7 blue, 6 red, 7 green; 10 green, 3 red; 9 red, 3 blue, 5 green
+Game 57: 5 blue, 11 red, 1 green; 13 red, 1 green, 2 blue; 2 blue, 4 red; 1 green, 10 red, 1 blue; 1 green, 8 red
+Game 58: 1 red, 2 green, 9 blue; 1 green, 1 blue, 1 red; 2 red, 6 blue, 2 green; 14 blue, 1 green, 1 red; 5 blue, 1 red, 2 green; 14 blue, 2 green
+Game 59: 9 green, 2 blue, 5 red; 9 red, 5 green; 10 red, 1 blue, 8 green
+Game 60: 8 blue, 6 red, 4 green; 3 red, 12 green, 9 blue; 4 blue, 5 red, 5 green; 4 red, 8 blue; 7 green, 12 blue, 6 red
+Game 61: 5 blue, 13 red, 1 green; 5 red, 5 blue; 1 red, 3 blue; 1 green, 9 red; 10 red, 3 blue, 1 green
+Game 62: 1 blue, 13 red; 4 blue, 5 red; 11 blue, 8 red, 1 green
+Game 63: 14 blue, 5 red; 9 blue, 14 green, 5 red; 3 red, 8 green, 15 blue; 4 blue, 15 green, 6 red
+Game 64: 13 red, 6 blue, 11 green; 12 red, 1 blue, 8 green; 1 red, 17 green; 13 red, 12 green, 7 blue
+Game 65: 4 red, 17 blue, 3 green; 2 green, 12 blue, 9 red; 2 green, 17 blue, 5 red; 1 red, 1 green, 4 blue; 9 red, 16 blue; 7 blue, 9 red
+Game 66: 10 blue, 10 green, 5 red; 10 green, 3 blue, 5 red; 1 red, 1 green, 10 blue; 2 green, 5 red, 20 blue; 8 blue, 11 green, 13 red; 2 green, 18 blue, 2 red
+Game 67: 6 red, 1 green; 5 red, 10 blue; 6 blue, 6 red
+Game 68: 4 green, 1 red, 5 blue; 5 red, 5 blue; 7 red, 6 green; 8 red, 1 blue
+Game 69: 2 blue, 11 red; 4 red, 6 green, 1 blue; 4 red, 1 blue, 14 green
+Game 70: 15 red, 8 blue, 5 green; 5 green, 2 red, 8 blue; 8 red, 3 green, 10 blue
+Game 71: 4 blue, 2 red; 12 green, 4 blue; 10 green
+Game 72: 3 blue, 4 green, 6 red; 6 red, 5 green, 8 blue; 10 red, 6 green, 5 blue; 1 green, 2 blue; 10 red, 5 blue, 4 green
+Game 73: 5 blue, 1 red; 1 green, 11 blue; 10 blue; 12 blue, 1 red; 1 red, 9 blue; 7 blue, 1 green, 1 red
+Game 74: 7 green, 6 blue, 7 red; 7 blue, 6 green, 15 red; 7 red, 5 blue, 1 green; 1 blue, 6 red, 8 green; 8 green, 14 red, 3 blue
+Game 75: 8 green, 3 red, 3 blue; 1 blue, 6 red, 7 green; 9 green, 3 blue; 3 blue, 9 green, 6 red; 4 blue, 1 red, 3 green; 4 green, 1 blue, 16 red
+Game 76: 4 blue, 3 green; 2 blue, 1 red, 6 green; 12 blue; 1 green, 14 blue
+Game 77: 5 green, 10 red, 11 blue; 3 red; 8 green, 6 red, 9 blue
+Game 78: 7 red, 7 green; 8 blue; 6 green, 7 red, 5 blue
+Game 79: 11 blue, 2 red, 4 green; 2 green, 3 red, 15 blue; 1 green, 15 blue, 1 red
+Game 80: 3 red, 17 green, 8 blue; 8 green, 10 blue; 4 green, 1 red, 14 blue
+Game 81: 17 green, 10 red, 10 blue; 9 green, 9 blue, 7 red; 11 red, 11 green, 4 blue; 15 blue, 5 red; 11 blue, 8 green, 15 red; 3 green, 16 red
+Game 82: 8 green, 9 blue, 1 red; 1 red, 8 green, 9 blue; 2 green, 12 blue
+Game 83: 2 green, 11 red, 20 blue; 20 blue, 1 green, 4 red; 2 green, 6 red, 20 blue; 17 blue, 10 red
+Game 84: 1 green, 9 red; 4 blue, 4 green; 1 green, 6 red, 14 blue
+Game 85: 5 red, 10 green, 9 blue; 8 blue, 3 green, 2 red; 4 blue, 14 green, 3 red; 5 red, 4 blue
+Game 86: 8 blue, 9 green, 5 red; 5 red, 10 green, 1 blue; 15 blue, 1 red, 2 green; 8 red, 8 blue, 10 green
+Game 87: 13 green, 2 red, 4 blue; 3 red, 11 green, 9 blue; 6 blue, 3 red, 12 green
+Game 88: 2 red, 7 blue, 3 green; 2 blue, 9 red; 9 red, 6 blue, 7 green; 6 green, 13 blue, 9 red; 6 green, 2 red, 15 blue; 1 red, 8 green, 7 blue
+Game 89: 11 red, 1 blue, 2 green; 6 blue, 5 green, 4 red; 15 red, 4 green, 5 blue; 11 red, 3 blue, 10 green; 6 blue, 13 green, 12 red
+Game 90: 2 red, 2 blue, 4 green; 2 red, 2 blue; 9 green, 1 red, 1 blue; 5 green, 1 red; 7 green, 2 red; 2 green, 1 blue
+Game 91: 5 blue, 3 red, 1 green; 1 red, 4 blue, 6 green; 6 blue, 6 green, 5 red
+Game 92: 16 green, 1 blue, 12 red; 18 green, 14 red, 1 blue; 16 red, 1 green; 4 blue, 16 red, 18 green
+Game 93: 9 red, 8 blue, 14 green; 1 blue, 1 green, 6 red; 4 blue, 4 red, 14 green
+Game 94: 11 green, 4 blue, 2 red; 1 red, 1 green, 1 blue; 4 red, 1 blue, 2 green
+Game 95: 5 blue, 2 red, 9 green; 5 blue, 8 green; 1 green, 15 blue; 5 red, 9 green, 5 blue; 3 green, 17 blue, 5 red
+Game 96: 2 green, 14 blue, 1 red; 3 green, 3 red, 14 blue; 2 red, 2 green, 13 blue
+Game 97: 2 green, 2 red; 2 blue, 1 green; 7 blue, 3 red
+Game 98: 2 red, 1 blue, 12 green; 2 blue, 10 green, 5 red; 11 green, 9 blue; 6 blue, 17 green; 7 blue, 9 green, 9 red; 1 red, 11 green, 9 blue
+Game 99: 2 green, 9 red, 1 blue; 3 green, 1 blue, 14 red; 5 green, 6 blue; 1 blue, 2 green, 3 red; 4 blue, 10 red, 1 green
+Game 100: 4 green, 4 blue, 15 red; 3 green, 1 red, 13 blue; 5 green, 5 blue, 10 red
diff --git a/lakefile.lean b/lakefile.lean
index ae16be8..f09586e 100644
--- a/lakefile.lean
+++ b/lakefile.lean
@@ -7,6 +7,8 @@ package «aoc-2023» where
 lean_lib «Day1» where
   -- add library configuration options here
 
+lean_lib «Day2» where
+
 lean_lib «Common» where
 
 @[default_target]