Solve 2024 day 22

2024/d22.py

@@ -0,0 +1,56 @@
+from lib import get_data
+from lib import ints
+from collections import defaultdict
+
+
+data = get_data(__file__)
+
+
+def secret(x):
+    x ^= x * 64
+    x %= 16777216
+
+    x ^= x // 32
+    x %= 16777216
+
+    x ^= x * 2048
+    x %= 16777216
+    return x
+
+
+def slice(xs, n):
+    return [slice for slice in zip(*[xs[i:] for i in range(n)])]
+
+
+codes = defaultdict(int)
+
+
+def int_seq(x):
+    xs = []
+    for _ in range(2000):
+        xs.append(x % 10)
+        x = secret(x)
+    ds = [a - b for a, b in zip(xs[1:], xs)]
+
+    seen = set()
+    for s in slice(list(zip(xs[1:], ds)), 4):
+        code = tuple([e[1] for e in s])
+        v = s[-1][0]
+        if not code in seen:
+            codes[code] += v
+            seen.add(code)
+
+
+for line in data.splitlines():
+    (x,) = ints(line)
+
+s = 0
+for line in data.splitlines():
+    (x,) = ints(line)
+    int_seq(x)
+    for _ in range(2000):
+        x = secret(x)
+    s += x
+
+print(s)
+print(max(codes.values()))

README.md

@@ -310,5 +310,9 @@ and focus. Of course, learning more algorithms and techniques helps.
 - Day 17: `17:34:16 23722      0       >24h  17778      0`
 - Day 18: `14:35:01 20398      0   14:37:18  19550      0`
 - Day 19: `00:14:37  2001      0   00:19:43   1584      0`
-- Day 20: `01:08:53   3637     0   01:53:01   2837      0`
-
+- Day 20: `01:08:53  3637      0   01:53:01   2837      0`
+- Day 21: `00:48:40   215      0          -      -      -`
+- Day 22: `00:13:04  1930      0   00:28:29    739      0`
+- Day 23:
+- Day 24:
+- Day 25: