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authorAndreas Grois <andi@grois.info>2025-10-12 18:44:32 +0200
committerAndreas Grois <andi@grois.info>2025-10-12 18:44:32 +0200
commit6aaa70943202efaa1e6b4ff8b6b8b6b94a564040 (patch)
tree171a1a1b459b82f016e756e8649767a2d1311160 /Day3.lean
parent2a9261d1ba962deff9fcc1784be44563af513af5 (diff)
Lean 4.19
Diffstat (limited to 'Day3.lean')
-rw-r--r--Day3.lean2
1 files changed, 1 insertions, 1 deletions
diff --git a/Day3.lean b/Day3.lean
index 00ef709..ae9cd2d 100644
--- a/Day3.lean
+++ b/Day3.lean
@@ -92,7 +92,7 @@ def parse (schematic : String) : Except String Schematic := do
def part1 (schematic : Schematic) : Nat :=
-- fast lookup: We need to know if a part is at a given coordinate
open Std(HashSet) in
- let partCoordinates := HashSet.insertMany HashSet.empty $ schematic.parts.map Part.position
+ let partCoordinates := HashSet.insertMany HashSet.emptyWithCapacity $ schematic.parts.map Part.position
let partNumbers := schematic.numbers.filter λnumber ↦
number.positions.any λposition ↦
position.adjacents.any partCoordinates.contains