.

Got this one ruined due to a post not masking
spoilers:

https://www.reddit.com/r/adventofcode/comments/1pkxibs/2025_day_25_part_1_still_pretty_clueless_why_its/

Basically, ignore the test case and just wing it by
asuming the 3x3 can be placed without overlaps. Id
the number of shapes * 3x3 is bigger than the available
canvas, it won't fit.

A naive first check to do before making premature
optimizations.

I would have gone the zip() hell route to prove
it actually works, but after grasping at the puzzle
input i realized it would tka a looong time to
calculate.

2025-python/output/day_09.py

@@ -1,5 +1,6 @@
 from math import inf
 from itertools import combinations
+
 from output import ints
 
 
@@ -41,59 +42,43 @@ def solve(data):
             break
         S = E
     V = V | W
-
-    def _within(a, b):
-        y1, x1 = a
-        y2, x2 = b
-        T = min(y1, y2)
-        R = max(x1, x2)
-        B = max(y1, y2)
-        L = min(x1, x2)
-        return all([
-            sum((r, L + 1) in W for r in range(T + 1, B)) % 2 == 0,
-            sum((r, R - 1) in W for r in range(T + 1, B)) % 2 == 0,
-            sum((T + 1, c) in W for c in range(L + 1, R)) % 2 == 0,
-            sum((B - 1, c) in W for c in range(L + 1, R)) % 2 == 0,
-        ])
-        
-    S = len(list(combinations(A, r=2)))
-    i = 0
     for a, b in combinations(A, r=2):
-        i += 1
-        if i % 100 == 0:
-            print(f"{str(i):>6} / {S}")
         y1, x1 = a
         y2, x2 = b
         x = abs(x1 - x2) + 1
         y = abs(y1 - y2) + 1
         p1 = max(p1, x * y)
-        if _within(a, b):
+        if _within(W, a, b, T, R, B, L):
             p2 = max(p2, max(p2, x * y))
     return p1, p2
 
 
+def _within(W, a, b, T, R, B, L):
+    y1, x1 = a
+    y2, x2 = b
+    for r in range(min(y1, y2) + 1, max(y1, y2)):
+        for c in range(min(x1, x2) + 1, max(x1, x2)):
+            if (r, c) in W:
+                continue
+            for s, e in [(T, r), (r, B)]:
+                z = sum((nr, c) in W for nr in range(s, e))
+                if z and z % 2 == 0:
+                    return False
+            for s, e in [(L, c), (c, R)]:
+                z = sum((r, nc) in W for nc in range(s, e))
+                if z and z % 2 == 0:
+                    return False
+    return True
 
 
 if __name__ == "__main__":
     with open("./input/09.txt", "r") as f:
         inp = f.read().strip()
 
-    in_p = """
-    7,1
-11,1
-11,7
-9,7
-9,5
-2,5
-2,3
-7,3    """.strip()
-
     p1, p2 = solve(inp)
 
     print(p1)
     print(p2)
 
-    assert p1 == 50
+    assert p1 == 4749838800
-    assert p2 == 24
+    assert p2 == 1624057680
-    # assert p1 == 4749838800
-    # assert p2 == 1624057680

2025-python/output/day_10.py

@@ -1,6 +1,6 @@
 import re
 import functools
-from math import inf
+from math import gcd, inf
 from pprint import pprint
 from collections import deque, Counter, defaultdict
 from heapq import heappop, heappush
@@ -12,13 +12,13 @@ from output import matrix, D, DD, ADJ, ints, sints, mhd, mdbg, vdbg, cw, ccw, bk
 def solve(data):
     r = r"^\[(.+)\] (.+) \{(.+)\}$"
     p1 = 0
-
+    p2 = 0
-    for j, line in enumerate(data.splitlines(), start=1):
+    for line in data.splitlines():
         il, b, j = re.findall(r, line)[0]
         B = [set(ints(s)) for s in b.split()]
         E = set([i for i, s in enumerate(il) if s == "#"])
-        J = ints(j)
+        j = tuple(ints(j))
-        
+
         p = 0
         L = set()
         while L != E:
@@ -31,20 +31,30 @@ def solve(data):
                         break
                 if L == E:
                     break
-        # p = 0
-        # L = [0] * len(J)
-        # while L != J:
-        #     p += 1
-        #     for bp in combinations(B, p):
-        #         L = set()
-        #         for b in bp:
-        #             L = L ^ b
-        #             if L == E:
-        #                 break
-        #         if L == E:
-        #             break
         p1 += p
-    p2 = None
+
+        @functools.cache
+        def _press(T):
+            if not any(T):
+                return 0
+            L = set(i for i, s in enumerate(T) if s % 2 == 1)
+            R = inf
+            for p in [bb for ii, bb in enumerate(B) if ii in L]:
+                tt = list(T)
+                for b in p:
+                    for i in b:
+                        tt[i] -= 1
+                if any(j < 0 for j in tt):
+                    continue
+                Th = tuple(j // 2 for j in tt)
+                n = _press(Th)
+                if n is None:
+                    continue
+                R = min(R, len(p) + 2 * n)
+            return R
+
+        p2 = _press(j)
+
     return p1, p2
 
 
@@ -62,7 +72,7 @@ if __name__ == "__main__":
 
     # uncomment to use AoC provided puzzle input
     with open("./input/10.txt", "r") as f:
-        inp = f.read().strip()
+        in_p = f.read().strip()
 
     # uncomment to do initial data processing shared by part 1-2
     p1, p2 = solve(inp)
@@ -74,5 +84,5 @@ if __name__ == "__main__":
 
     # uncomment and replace 0 with actual output to refactor code
     # and ensure nonbreaking changes
-    # assert p1 == 0
+    # assert p1 == 466
-    # assert p2 == 0
+    # assert p2 == 17214

2025-python/output/day_11.py

@@ -3,10 +3,10 @@ from collections import defaultdict
 
 
 def solve(data):
-    G = defaultdict(list)
+    G = defaultdict(set)
     for line in data.splitlines():
         f, *t = line.split()
-        G[f[:-1]] = t
+        G[f[:-1]] = set(t)
 
     @functools.cache
     def _traverse(k, fasttrack=True, fft=False, dac=False):
@@ -15,7 +15,7 @@ def solve(data):
         return sum(
             _traverse(nk, fasttrack, fft or k == "fft", dac or k == "dac")
             for nk in G[k]
-    )
+        )
 
     return _traverse("you"), _traverse("svr", fasttrack=False)