Poetry stuff.

src/holt59/aoc/2022/day20.py

@@ -0,0 +1,74 @@
+from __future__ import annotations
+
+import sys
+
+
+class Number:
+    current: int
+    value: int
+
+    def __init__(self, value: int):
+        self.current = 0
+        self.value = value
+
+    def __str__(self):
+        return str(self.value)
+
+    def __repr__(self):
+        return str(self)
+
+
+def decrypt(numbers: list[Number], key: int, rounds: int) -> int:
+    numbers = numbers.copy()
+    original = numbers.copy()
+
+    for index, number in enumerate(numbers):
+        number.current = index
+
+    for _ in range(rounds):
+        for number in original:
+            index = number.current
+            offset = (number.value * key) % (len(numbers) - 1)
+            target = index + offset
+
+            # need to wrap
+            if target >= len(numbers):
+                target = offset - (len(numbers) - index) + 1
+
+                for number_2 in numbers[target:index]:
+                    number_2.current += 1
+
+                numbers = (
+                    numbers[:target]
+                    + [number]
+                    + numbers[target:index]
+                    + numbers[index + 1 :]
+                )
+            else:
+                for number_2 in numbers[index : target + 1]:
+                    number_2.current -= 1
+
+                numbers = (
+                    numbers[:index]
+                    + numbers[index + 1 : target + 1]
+                    + [number]
+                    + numbers[target + 1 :]
+                )
+            number.current = target
+
+    index_of_0 = next(
+        filter(lambda index: numbers[index].value == 0, range(len(numbers)))
+    )
+    return sum(
+        numbers[(index_of_0 + offset) % len(numbers)].value * key
+        for offset in (1000, 2000, 3000)
+    )
+
+
+numbers = [Number(int(x)) for i, x in enumerate(sys.stdin.readlines())]
+
+answer_1 = decrypt(numbers, 1, 1)
+print(f"answer 1 is {answer_1}")
+
+answer_2 = decrypt(numbers, 811589153, 10)
+print(f"answer 2 is {answer_2}")