2016/11

y2016/p11.py

+import re
+import sys
+
+
+def display(state):
+    ele, floors = state
+    for i, floor in list(enumerate(floors))[::-1]:
+        _ = ['E' if ele == i else ' ']
+        _ += [d if d in floor else '..' for d in sorted(devices)]
+        print(' '.join(_))
+    print()
+
+
+def checks(elevator, floors):
+    for fl in floors:
+        vulnerable = {d for d in fl if d == d.lower() and d.upper() not in fl}
+        dangerous = {d for d in fl if d == d.upper()}
+        if vulnerable and dangerous:
+            yield False
+
+
+def moves(ith, floors):
+    for jth in {ith - 1, ith + 1} - {-1, 4}:
+        for stuff in [{a, b} for a in floors[ith] for b in floors[ith]]:
+            new = (jth, tuple(
+                (floor | stuff) if ith == jth else (floor - stuff)
+                for ith, floor in enumerate(floors)
+            ))
+            if all(checks(*new)):
+                yield new
+
+
+text = sys.stdin.read()
+start = [
+    frozenset(
+        word[:2].upper() if not word.endswith('-') else word[:2]
+        for word in re.findall(r'\w+ium-?', ln)
+    )
+    for ln in text.splitlines()
+]
+start[2] -= {'PR', 'RU', 'pr', 'ru'}
+# start[0] |= {'EE', 'ee', 'DD', 'dd'}
+devices = frozenset({device for floor in start for device in floor})
+
+edge = {(0, tuple(start))}
+goal = (3, tuple([frozenset(), frozenset(), frozenset(), devices]))
+seen = {}
+while goal not in seen:
+    edge = {new: old for old in edge for new in moves(*old) if new not in seen}
+    if not edge:
+        raise RuntimeError('empty')
+    seen = {**edge, **seen}
+    print(len(edge))
+
+seq = []
+while goal != (0, tuple(start)):
+    seq.append(goal)
+    goal = seen[goal]
+seq.append(goal)
+seq.reverse()
+
+for i, state in enumerate(seq):
+    print(i)
+    display(state)