Solve 2020 day 24 and 25 and 2018 day 23 part 2

2018/d23.py

@@ -1,32 +1,45 @@
-from lib import get_data, str_to_ints
+from lib import get_data, ints
-
-def dist(a, b):
-    return sum(abs(x - y) for x, y in zip(a[:3], b[:3]))
 
 data = get_data(__file__)
-data = """pos=<10,12,12>, r=2
-pos=<12,14,12>, r=2
-pos=<16,12,12>, r=4
-pos=<14,14,14>, r=6
-pos=<50,50,50>, r=200
-pos=<10,10,10>, r=5
-"""
 
-max_bot = None
+X, Y, Z, RADIUS = 0, 1, 2, 3
-bots = []
-for line in data.splitlines():
-    xs = str_to_ints(line)
-    if max_bot is None:
-        max_bot = xs
-    elif xs[3] > max_bot[3]:
-        max_bot = xs
-    bots.append(xs)
 
-assert max_bot is not None
 
-t = 0
+def dist(a, b):
+    return sum(abs(x - y) for x, y in zip(a[:RADIUS], b[:RADIUS]))
+
+
+bots = [ints(line) for line in data.splitlines()]
+max_bot = max(bots, key=lambda b: b[RADIUS])
 r = max_bot[3]
-for bot in bots:
+t = sum(1 for bot in bots if dist(bot, max_bot) <= r)
-    if dist(bot, max_bot) <= r:
-        t += 1
 print(t)
+
+from z3 import Int, If, Abs, Sum, IntVal, Optimize, set_param
+
+
+x = Int("x")
+y = Int("y")
+z = Int("z")
+
+z3zero = IntVal(0)
+z3one = IntVal(1)
+n_out_of_range = Int("n_out_of_range")
+dist_origin = Int("dist_origin")
+
+bots_out_of_range = [
+    If(Abs(b[X] - x) + Abs(b[Y] - y) + Abs(b[Z] - z) > b[RADIUS], z3one, z3zero)
+    for b in bots
+]
+
+set_param("parallel.enable", True)
+
+opt = Optimize()
+opt.add(n_out_of_range == Sum(bots_out_of_range))
+opt.add(dist_origin == Abs(x) + Abs(y) + Abs(z))
+opt.minimize(n_out_of_range)
+opt.minimize(dist_origin)
+
+res = opt.check()
+m = opt.model()
+print(m[dist_origin])

2020/d24.py

@@ -0,0 +1,59 @@
+from lib import get_data, add2
+from collections import defaultdict
+
+DIRS = {
+    "e": (0, 2),
+    "w": (0, -2),
+    "se": (1, 1),
+    "sw": (1, -1),
+    "nw": (-1, -1),
+    "ne": (-1, 1),
+}
+
+data = get_data(__file__)
+
+tiles_black = set()
+
+for row in data.splitlines():
+    row = row.strip()
+    i = 0
+    pos = (0, 0)
+    while i < len(row):
+        d = None
+        if row[i] in DIRS:
+            d = DIRS[row[i]]
+            i += 1
+        elif "".join(row[i : i + 2]) in DIRS:
+            d = DIRS["".join(row[i : i + 2])]
+            i += 2
+        else:
+            assert False
+        assert d is not None
+        pos = add2(pos, d)
+    if pos in tiles_black:
+        tiles_black.remove(pos)
+    else:
+        tiles_black.add(pos)
+
+print(len(tiles_black))
+
+for _ in range(100):
+    nbs = defaultdict(int)
+    for bt in tiles_black:
+        for d in DIRS.values():
+            nb = add2(bt, d)
+            nbs[nb] += 1
+    new_tiles_black = set()
+    for pos, count in nbs.items():
+        if pos in tiles_black:
+            if count == 0 or count > 2:
+                pass
+            else:
+                new_tiles_black.add(pos)
+        else:
+            if count == 2:
+                new_tiles_black.add(pos)
+
+    tiles_black = new_tiles_black
+
+print(len(tiles_black))

2020/d25.py

@@ -0,0 +1,32 @@
+from lib import get_data, ints
+
+data = get_data(__file__)
+a, b = ints(data)
+
+v = 1
+subject_number = 7
+al, bl = None, None
+
+for loop in range(100_000_000):
+    v *= subject_number
+    v %= 20201227
+    if al is None and v == a:
+        al = loop + 1
+    if bl is None and v == b:
+        bl = loop + 1
+
+    if al and bl:
+        break
+
+assert al is not None
+assert bl is not None
+# print(al, bl)
+
+v = 1
+subject_number = b
+for _ in range(al):
+    v *= subject_number
+    v %= 20201227
+
+print(v)
+

README.md

@@ -162,8 +162,8 @@ Solutions and utility script for Advent of Code challenges in Python.
 - Day 21: 23:02 (Simply to slow)
 - Day 22: 45:49 (Simple and too slow)
 - Day 23: 105:00 (Sad)
-- Day 24:
+- Day 24: 15:38 (Close to leaderboard)
-- Day 25:
+- Day 25: 14:40 (Way too slow)
 
 ## AoC 2022