Day 9

2020/9/main.py

@@ -0,0 +1,54 @@
+def preamble_generator(dataset):
+	preamble_length = len(dataset)
+	for i in range(0, preamble_length):
+		for j in range(i + 1, preamble_length):
+			yield dataset[i] + dataset[j]
+
+
+def is_contained_in(preamble_dataset, value):
+	for x in preamble_generator(preamble_dataset):
+		if value == x:
+			return True
+	return False
+
+
+def get_first_noncompliant_no(dataset, preamble_length):
+	for i in range(preamble_length, len(dataset)):
+		preamble = dataset[i - preamble_length:i]
+		value = dataset[i]
+		if not is_contained_in(preamble, value):
+			return value
+
+	assert False, "Wtf?"
+
+
+def get_range(nc, dataset):
+	l = len(dataset)
+	for i in range(0, l):
+		for j in range(i, l):
+			ds = dataset[i:j]
+			s = sum(ds)
+			if s > nc:
+				break
+
+			if nc == s:
+				return ds
+
+	assert False, "Wtf?"
+
+
+def process(filename, preamble_length):
+	with open(filename, "r", encoding="utf-8") as f:
+		nums = [int(x) for x in f]
+
+	nc = get_first_noncompliant_no(nums, preamble_length)
+	print(f"1: First non-compliant no. in {filename} is {nc}.")
+
+	r = get_range(nc, nums)
+	a = min(r) + max(r)
+	print(f"2: Answer is {a}.")
+
+
+process("test.txt", 5)
+print("-"*80)
+process("data.txt", 25)

2020/9/test.txt

@@ -0,0 +1,20 @@
+35
+20
+15
+25
+47
+40
+62
+55
+65
+95
+102
+117
+150
+182
+127
+219
+299
+277
+309
+576