Implement 2024 day 22

Author: bertptrs

2024/src/aoc/days/day22.py

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+from collections import defaultdict
+
+import numpy
+from numpy.lib.stride_tricks import sliding_window_view
+
+from . import SeparateRunner
+
+
+def advance(secrets: numpy.array) -> numpy.array:
+    new_secrets = (secrets ^ (secrets << 6)) & 0xFFFFFF
+    new_secrets ^= new_secrets >> 5
+    new_secrets ^= new_secrets << 11
+    new_secrets &= 0xFFFFFF
+
+    return new_secrets
+
+
+class DayRunner(SeparateRunner):
+    @classmethod
+    def part1(cls, input: str) -> int:
+        secrets = numpy.fromstring(input, dtype=int, sep="\n")
+
+        for _ in range(2000):
+            secrets = advance(secrets)
+
+        return secrets.sum()
+
+    @classmethod
+    def part2(cls, input: str) -> int:
+        secrets = numpy.fromstring(input, dtype=int, sep="\n")
+
+        progression = [secrets]
+
+        for _ in range(2000):
+            secrets = advance(secrets)
+            progression.append(secrets)
+
+        field = numpy.stack(progression, axis=-1) % 10
+        delta = field[:, 1:] - field[:, :-1]
+
+        per_signal = defaultdict(int)
+
+        for row_scores, row_deltas in zip(field, delta):
+            seen = set()
+
+            for window, price in zip(
+                sliding_window_view(row_deltas, 4), row_scores[4:]
+            ):
+                key = tuple(window)
+                if key not in seen:
+                    seen.add(key)
+                    per_signal[key] += price
+
+        return max(per_signal.values())

2024/tests/samples/22.1.txt

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+1
+10
+100
+2024

2024/tests/samples/22.2.txt

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+1
+2
+3
+2024

2024/tests/test_day22.py

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+from aoc.days.day22 import DayRunner
+
+from . import get_data
+
+
+def test_sample_part1() -> None:
+    assert DayRunner.part1(get_data(22, 1)) == 37327623
+
+
+def test_sample_part2() -> None:
+    assert DayRunner.part2(get_data(22, 2)) == 23