Inefficient but correct solution for day 22/2

2024/day22/code.py

@@ -19,26 +19,30 @@ if __name__ == '__main__':
     # challenge 1
     res1 = 0
     changes, values = {}, {}
+    change_set = set([])
     for n in nums:
         secret = n
-        changes[n] = [0] * 2000
+        changes[n] = [[] for i in range(2000)]
         values[n] = [0] * 2000
         ob = int(str(secret)[-1])
         for i in range(2000):
             secret = prg(secret)
             bananas = int(str(secret)[-1])
-            changes[n][i] = bananas - ob
+            for j in range(i,min(2000,i+4)):
+                changes[n][j].append(bananas - ob)
             values[n][i] = bananas
             ob = bananas
         res1 += secret
 
     print(f"challenge 1:\n{res1}\n")
-    # for i, c in enumerate(changes[123][3:10]):
-    #     if c > 0: print(changes[123][i:i+4])
-    print(changes[123][:10])
 
-    # challenge 2
+    # challenge 2 (could be more efficient i guess)
+    res2 = 0
+    for n in nums:
+        change_set = change_set.union(set([tuple(c) if c[-1] > 1 else () for c in changes[n]]))
+    for c in list(change_set):
+        if c != () and c[-1] > 1 and sum([list(c) in changes[num] for num in nums]) > 100:
+            res2 = max(sum([values[num][changes[num].index(list(c))] if list(c) in changes[num] else 0 for num in nums]), res2)
 
-    res2 = ""
     print(f"challenge 2:\n{res2}")