2017 progress.

2017/d7.py

@@ -0,0 +1,63 @@
+from dataclasses import dataclass
+from collections import defaultdict
+import sys
+
+
+@dataclass
+class Disc:
+    name: str
+    value: int
+    holds: list
+
+
+discs = {}
+data = open(0).read().strip()
+
+
+for line in data.splitlines():
+    right = None
+    if "->" in line:
+        left, right = line.split(" -> ")
+    else:
+        left = line
+    name, value = left.split()
+    value = int(value[1:-1])
+    d = Disc(name, value, [])
+    if right is not None:
+        for r in right.split(", "):
+            d.holds.append(r)
+    discs[d.name] = d
+
+
+alldiscs = set(discs.keys())
+for d in discs.values():
+    for h in d.holds:
+        alldiscs.remove(h)
+assert len(alldiscs) == 1
+top_disc = alldiscs.pop()
+print(top_disc)
+
+
+def weight(disc_name):
+    disc = discs[disc_name]
+    child_weights = {}
+    for child_disc_name in disc.holds:
+        child_weights[child_disc_name] = weight(child_disc_name)
+
+    if not all([w == list(child_weights.values())[0] for w in child_weights.values()]):
+        values = defaultdict(list)
+        for child_name, child_value in child_weights.items():
+            values[child_value].append(child_name)
+
+        same_weight, other_weight = 0, 0
+        for child_weight, children in values.items():
+            if len(children) == 1:
+                other_weight = child_weight
+            else:
+                same_weight = child_weight
+        weight_delta = other_weight - same_weight
+        print(discs['dqwocyn'].value - weight_delta)
+        sys.exit(0)
+    return disc.value + sum(child_weights.values())
+
+weight(top_disc)