🚌

VERSION

@@ -1 +1 @@
-🚩
+🚌

y2023/p18.py

@@ -3,7 +3,7 @@ def perimeter(pts):
     for i in range(len(pts)):
         dist = pts[i - 1] - pts[i]
         n += abs(dist.real) + abs(dist.imag)
-    return int(n)
+    return int(n / 2) + 1
 
 
 def area(pts):
@@ -23,7 +23,7 @@ for line in text.splitlines():
     n = int(n)
     d = 1j ** 'RDLU'.index(d)
     pts.append(pts[-1] + d * n)
-print(area(pts) + perimeter(pts) // 2 + 1)
+print(area(pts) + perimeter(pts))
 
 pts = [0]
 for line in text.splitlines():
@@ -31,7 +31,7 @@ for line in text.splitlines():
     n = int(s[2:7], 16)
     d = 1j ** int(s[7])
     pts.append(pts[-1] + d * n)
-print(area(pts) + perimeter(pts) // 2 + 1)
+print(area(pts) + perimeter(pts))
 
 
 # def render(graph, default='.'):

y2023/p20.py

@@ -0,0 +1,79 @@
+import math
+
+
+def send(parent, sender, signal):
+    match kinds[sender], signal:
+        case 'rx' | 'output', _:
+            signal = None
+        case 'button' | 'broadcaster', _:
+            pass
+        case '%', 0:
+            signal = state[sender] = int(not state[sender])
+        case '%', 1:
+            signal = None
+        case '&', _:
+            state[sender][parent] = signal
+            seen = set(state[sender].values())
+            signal = 0 if seen == {1} else 1
+        case default:
+            raise RuntimeError(default)
+
+    if signal is not None:
+        for target in targets[sender]:
+            # print(sender, signal, target)
+            output.append(signal)
+            yield (sender, target, signal)
+
+
+def deps(p):
+    seen = set()
+    state = {p}
+    while state:
+        seen |= state
+        state = {k for p in state for k, vs in targets.items() if p in vs and k not in seen}
+    return tuple(sorted(seen))
+
+
+text = open(0).read()
+targets = {'button': ['broadcaster']}
+kinds = {'button': 'button', 'rx': 'rx', 'output': 'output'}
+for line in text.splitlines():
+    src, dst = line.split(' -> ')
+    dst = dst.split(', ')
+    if src == 'broadcaster':
+        label = kind = 'broadcaster'
+    else:
+        label, kind = src[1:], src[0]
+    targets[label] = dst
+    kinds[label] = kind
+state = {}
+state |= {l: 0 for l, k in kinds.items() if k == '%'}
+state |= {l: {i: 0 for i, ts in targets.items() if l in ts} for l, k in kinds.items() if k == '&'}
+
+families = {}
+for k in kinds:
+    families.setdefault(hash(deps(k)), []).append(k)
+families = {tuple(vs): set() for vs in families.values() if len(vs) > 1}
+
+seq = []
+seen = set()
+while True:
+    output = []
+    active = [(None, 'button', 0)]
+    while active:
+        active = [new for old in active for new in send(*old)]
+    seq.append(output)
+
+    before = [len(vs) for vs in families.values()]
+    for ks in families:
+        families[ks].add(hash(str([state[k] for k in ks])))
+    after = [len(vs) for vs in families.values()]
+    if before == after:
+        break
+
+    if len(seq) == 1000:
+        # pt 1
+        los = [sum(v == 0 for v in vs) for vs in seq]
+        his = [sum(v == 1 for v in vs) for vs in seq]
+        print(sum(los[i % len(los)] for i in range(1000)) * sum(his[i % len(his)] for i in range(1000)))
+print(math.prod(after))