11: Py: Cleanup and avoid eval()

11/solution.py

@@ -3,45 +3,51 @@
 import sys
 from copy import deepcopy
 from math import prod
+from operator import add, mul
+
+def monkey_business(monkeys, rounds, part2):
+    monkeys = deepcopy(monkeys)
+
+    ohmygodihateyoueric = prod(m["test"] for m in monkeys)
+    for it in range(rounds):
+        for m in monkeys:
+            for old in m["items"]:
+                m["count"] += 1
+                new = m["op"](old)
+                if part2:
+                    new %= ohmygodihateyoueric
+                else:
+                    new //= 3
+                monkeys[m[not (new % m["test"])]]["items"].append(new)
+            m["items"].clear()
+
+    return prod(sorted(m["count"] for m in monkeys)[-2:])
+
+def op2func(opstr):
+    params = opstr.split()
+    op = add if params[1] == "+" else mul
+    if params[2] == "old":
+        func = lambda old: op(old, old)
+    else:
+        func = lambda old: op(old, int(params[2]))
+    return func
 
 monkeys = []
 
-for l in sys.stdin:
-    l = l.strip()
-    if l.startswith("M"):
-        monkeys.append({})
-        monkeys[-1]["count"] = 0
-    elif l.startswith("S"):
-        monkeys[-1]["items"] = [int(x) for x in l[16:].split(", ")]
-    elif l.startswith("O"):
-        monkeys[-1]["op"] = l[17:]
-    elif l.startswith("T"):
-        monkeys[-1]["test"] = int(l[19:])
-    elif l.startswith("If t"):
-        monkeys[-1][True] = int(l[25:])
-    elif l.startswith("If f"):
-        monkeys[-1][False] = int(l[26:])
+for a, b in [l.strip().split(":") for l in sys.stdin if ":" in l]:
+    match a.split():
+        case ["Monkey", _]:
+            monkeys.append({})
+            monkeys[-1]["count"] = 0
+        case ["Starting", "items"]:
+            monkeys[-1]["items"] = [int(x) for x in b.split(", ")]
+        case ["Operation"]:
+            monkeys[-1]["op"] = op2func(b.split(" = ")[1])
+        case ["Test"]:
+            monkeys[-1]["test"] = int(b.rsplit(" ", 1)[-1])
+        case ["If", condition]:
+            monkeys[-1][condition == "true"] = int(b.rsplit(" ", 1)[-1])
 
-monkeysG = deepcopy(monkeys)
-
-for it in range(20):
-    for m in monkeys:
-        for old in m["items"]:
-            m["count"] += 1
-            new = eval(m["op"]) // 3
-            monkeys[m[not (new % m["test"])]]["items"].append(new)
-        m["items"].clear()
-
-ohmygodihateyoueric = prod(m["test"] for m in monkeys)
-for it in range(10000):
-    for m in monkeysG:
-        for old in m["items"]:
-            m["count"] += 1
-            new = eval(m["op"]) % ohmygodihateyoueric
-            monkeysG[m[not (new % m["test"])]]["items"].append(new)
-        m["items"].clear()
-
-resS = sorted(m["count"] for m in monkeys)[-2:]
-resG = sorted(m["count"] for m in monkeysG)[-2:]
-
-print(f"Silver: {prod(resS)}\nGold: {prod(resG)}")
+p1 = monkey_business(monkeys, 20, False)
+p2 = monkey_business(monkeys, 10000, True)
+print(f"Silver: {p1}\nGold: {p2}")