Solve 2024:22 p1-2 "Monkey Market"

Part 1 was relatively easy, 2 was harder.

> So, by asking the monkey to sell the *first time*
> each buyer's prices go down 2, then up 1, then
> down 1, then up 3, you would get 23 (7 + 7 + 9)
> bananas!

Emphazis mine. Earlier versions of the code missed
this fact, and added all occourences of the sequence.
providing a answer that is too high.

2024-python/output/day_22.py

@@ -0,0 +1,44 @@
+import math
+from collections import deque, defaultdict
+
+from output import ints
+
+
+def solve(data):
+    s = [(n, n % 10) for n in ints(data)]
+    bananas = defaultdict(int)
+    sum_2000th_secrets = 0
+    for j, n in enumerate(s):
+        seen = set()
+        L = deque()
+        for i in range(2000):
+            prize, dff = calc(*n)
+            if len(L) == 4:
+                L.popleft()
+            L.append(dff)
+            if len(L) == 4:
+                if tuple(L) not in seen:
+                    seen.add(tuple(L))
+                    bananas[tuple(L)] += prize % 10
+            n = prize, dff
+        sum_2000th_secrets += prize
+    max_bananas = max(bananas.values())
+    return sum_2000th_secrets, max_bananas
+
+
+def calc(i, d=0):
+    a = i % 10
+    i = ((i * 64) ^ i) % 16777216
+    i = (math.floor(i / 32) ^ i) % 16777216
+    i = ((i * 2048) ^ i) % 16777216
+    return i, (i % 10) - a
+
+
+if __name__ == "__main__":
+    with open("./input/22.txt", "r") as f:
+        inp = f.read().strip()
+
+    p1, p2 = solve(inp)
+
+    print(p1)
+    print(p2)