day 16

2021/16.py

@@ -0,0 +1,60 @@
+with open('./2021/16.input') as input_file:
+    input_data = input_file.read()
+ll = input_data
+
+d = bin(int(ll, 16))[2:]
+while len(d) < 4 * len(ll):
+	d = '0' + d
+
+def peek(data, n):
+	ret = data[0][:n]
+	data[0] = data[0][n:]
+	return ret
+
+sumofversions = 0
+def parse(data):
+	global sumofversions
+	
+	version = int(peek(data, 3), 2)
+	sumofversions += version
+
+	tid = int(peek(data, 3), 2)
+	if tid == 4:
+		t = []
+		while True:
+			cnt, *v = peek(data, 5)
+			t += v
+			if cnt == '0':
+				break
+		return int("".join(t), 2)
+
+	ltid = peek(data, 1)[0]
+	spv = []
+	if ltid == '0':
+		subpacketslen = int(peek(data, 15), 2)
+		subpackets = [peek(data, subpacketslen)]
+		while subpackets[0]:
+			spv.append(parse(subpackets))
+	else:
+		spv = [parse(data) for i in range(int(peek(data, 11), 2))]
+	if tid == 0:
+		return sum(spv)
+	elif tid == 1:
+		p = 1
+		for x in spv:
+			p *= x
+		return p
+	elif tid == 2:
+		return min(spv)
+	elif tid == 3:
+		return max(spv)
+	elif tid == 5:
+		return int(spv[0] > spv[1])
+	elif tid == 6:
+		return int(spv[0] < spv[1])
+	elif tid == 7:
+		return int(spv[0] == spv[1])
+
+p2 = parse([d])
+print(sumofversions)
+print(p2)