.

For p1 a BFS algorithm is fast enough. For pt 2,
for the third day in a row, it did not work.

I caved in and used recursion and memoisation for
DFS instead, instantly fast as lightning.

I finished by making the pt 2 code compatible with
pt 1.

2025-python/output/day_09.py

@@ -1,6 +1,5 @@
 from math import inf
 from itertools import combinations
-
 from output import ints
 
 
@@ -42,43 +41,59 @@ 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(W, a, b, T, R, B, L):
+        if _within(a, b):
             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 == 4749838800
-    assert p2 == 1624057680
+    assert p1 == 50
+    assert p2 == 24
+    # assert p1 == 4749838800
+    # assert p2 == 1624057680

2025-python/output/day_10.py

@@ -1,4 +1,6 @@
 import re
+import functools
+from math import inf
 from pprint import pprint
 from collections import deque, Counter, defaultdict
 from heapq import heappop, heappush
@@ -10,20 +12,38 @@ from output import matrix, D, DD, ADJ, ints, sints, mhd, mdbg, vdbg, cw, ccw, bk
 def solve(data):
     r = r"^\[(.+)\] (.+) \{(.+)\}$"
     p1 = 0
-    for line in data.splitlines():
-        il, b, _j = re.findall(r, line)[0]
+
+    for j, line in enumerate(data.splitlines(), start=1):
+        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 == "#"])
-        Q = [(b, set(), 0) for b in B]
-        while Q:
-            b, lit, p = Q.pop(0)
-            if lit == E:
-                p1 += p
-                break
-            for nb in B:
-                if nb == b:
-                    continue
-                Q.append((nb, lit ^ b, p + 1))
+        J = ints(j)
+        
+        p = 0
+        L = set()
+        while L != E:
+            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
+        # 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
     return p1, p2
 
@@ -49,8 +69,8 @@ if __name__ == "__main__":
 
     print(p1)
     os.system(f"echo {p1} | wl-copy")
-    # print(p2)
-    # os.system(f"echo {p2} | wl-copy")
+    print(p2)
+    os.system(f"echo {p2} | wl-copy")
 
     # uncomment and replace 0 with actual output to refactor code
     # and ensure nonbreaking changes

2025-python/output/day_11.py

@@ -0,0 +1,33 @@
+import functools
+from collections import defaultdict
+
+
+def solve(data):
+    G = defaultdict(list)
+    for line in data.splitlines():
+        f, *t = line.split()
+        G[f[:-1]] = t
+
+    @functools.cache
+    def _traverse(k, fasttrack=True, fft=False, dac=False):
+        if k == "out":
+            return fasttrack or (fft and dac)
+        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)
+
+
+if __name__ == "__main__":
+    with open("./input/11.txt", "r") as f:
+        inp = f.read().strip()
+
+    p1, p2 = solve(inp)
+
+    print(p1)
+    print(p2)
+
+    assert p1 == 649
+    assert p2 == 458948453421420