Solve 2021 day 4 and 5

2021/d4.py

@@ -0,0 +1,52 @@
+from lib import get_data
+from lib import ints
+
+data = get_data(__file__).strip()
+
+boards = []
+numbers = None
+for i, p in enumerate(data.split("\n\n")):
+    if i == 0:
+        numbers = ints(p)
+    else:
+        board = []
+        for line in p.splitlines():
+            board.append(ints(line))
+        boards.append(board)
+
+assert numbers is not None
+first_won = None
+last_won = None
+boards_done = list()
+for n in numbers:
+    for i in range(len(boards)):
+        if i in boards_done:
+            continue
+        board = boards[i]
+        board = [[f if n != f else None for f in row] for row in board]
+        boards[i] = board
+        for row in board:
+            if all(cell is None for cell in row):
+                if not i in boards_done:
+                    boards_done.append(i)
+        for col in zip(*board):
+            if all(cell is None for cell in col):
+                if not i in boards_done:
+                    boards_done.append(i)
+
+        if len(boards_done) > 0 and first_won is None:
+            first_won = (i, n)
+
+        if len(boards_done) == len(boards):
+            last_won = (i, n)
+            break
+    if len(boards_done) == len(boards):
+        break
+
+assert first_won is not None
+assert last_won is not None
+
+for i, n in [first_won, last_won]:
+    board = boards[i]
+    a = sum([sum([n if n is not None else 0 for n in row]) for row in board])
+    print(a * n)

2021/d5.py

@@ -0,0 +1,39 @@
+from lib import get_data
+from lib import ints
+from collections import defaultdict
+
+data = get_data(__file__).strip()
+
+counts = defaultdict(int)
+for line in data.splitlines():
+    x1, y1, x2, y2 = ints(line)
+    if x1 == x2 or y1 == y2:
+        if x1 == x2:
+            for y in range(min(y1, y2), max(y1, y2) + 1):
+                counts[(x1, y)] += 1
+        elif y1 == y2:
+            for x in range(min(x1, x2), max(x1, x2) + 1):
+                counts[(x, y1)] += 1
+        else:
+            assert False
+
+r = sum(1 for v in counts.values() if v > 1)
+print(r)
+
+
+for line in data.splitlines():
+    x1, y1, x2, y2 = ints(line)
+    if x1 == x2 or y1 == y2:
+        pass
+    else:
+        dx = 1 if x2 > x1 else -1
+        dy = 1 if y2 > y1 else -1
+
+        while (x1, y1) != (x2, y2):
+            counts[(x1, y1)] += 1
+            x1 += dx
+            y1 += dy
+        counts[(x2, y2)] += 1
+
+r = sum(1 for v in counts.values() if v > 1)
+print(r)

README.md

@@ -175,7 +175,9 @@ Solutions and utility script for Advent of Code challenges in Python.
 - Day 1:  4:01   (Haha. Why am I so bad?!?!)
 - Day 2:  6:36   (Okay. I might as well stop doing these.)
 - Day 3: 23:46   (How long can I take when I try to take long?)
-- Day 4:
+- Day 4: 22:18   (No way. Such stupid bugs.)
+- Day 5: 13:30   (Decent, but obviously too slow.)
+- Day 6:
 
 ## AoC 2022