1 files changed, 11 insertions, 4 deletions
diff --git a/4.py b/4.py
index 3cafb8b..b740d7b 100644
--- a/4.py
+++ b/4.py
@@ -6,7 +6,9 @@ class Cell:
     num: int
     marked: bool = False
 
-def bingo(board):
+Board = list[list[Cell]]
+
+def bingo(board: Board) -> bool:
     for row in board:
         if all(cell.marked for cell in row):
             return True
@@ -15,10 +17,13 @@ def bingo(board):
             return True
     return False
 
-def solve(nums, boards):
-    won = set()
-    wins = []
+def solve(nums: list[int], boards: list[Board]) -> tuple[int, int]:
+    won: set[int] = set()
+    wins: list[int] = []
+    num: int
     for num in nums:
+        i: int
+        board: Board
         for i, board in enumerate(boards):
             total = 0
             for row in board:
@@ -32,6 +37,8 @@ def solve(nums, boards):
                 wins.append(num * total)
     return wins[0], wins[-1]
 
+nums: str | list[int]
+boards: list[str] | list[Board]
 nums, *boards = open_day(4).read().rstrip().split('\n\n')
 nums = list(map(int, nums.split(',')))
 boards = [[[Cell(int(n)) for n in l.split()] for l in b.split('\n')] for b in boards]