2025(02): solve part 2

Grafpuzzels zijn het soms.

2025/02/part2.py

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+def is_invalid_id(num):
+	# print("Testing", num)
+	num_str = str(num)
+	num_len = len(num_str)
+	for period in range(1, num_len):
+		# print("period =", period)
+		# Period should be a factor of num_len
+		if num_len % period != 0:
+			continue
+
+		# Start with True, make False when it fails
+		palin = True
+		for idx in range(period, num_len, period):
+			# print("idx =", idx)
+			# print(num_str[:period], "=?=", num_str[idx:idx + period])
+			if num_str[:period] != num_str[idx:idx + period]:
+				# print(False)
+				palin = False
+				# print(False)
+		if palin:
+			# print("Returning palin")
+			return True
+	
+	# No period has yielded repetition:
+	return False
+			
+if __name__ == "__main__":
+	with open("input", "r") as fp:
+		rangestrs = fp.read().split(",")
+		ranges = []
+		for rangestr in rangestrs:
+			a, b = rangestr.split("-")
+			a_int, b_int = int(a), int(b)
+			ranges.append((a, b))
+			assert a_int < b_int, f"Range invalid: {a} is not smaller than {b}"
+
+		illegal_counter = 0
+		illegal_sum = 0
+		for a, b in ranges:
+			a_int, b_int = int(a), int(b)
+			for num in range(a_int, b_int + 1):
+				if is_invalid_id(num):
+					print(num, "is a palindrome thing")
+					illegal_counter += 1
+					illegal_sum += num
+				# num_str = str(num)
+				# num_len = len(num_str)
+				# palin = False
+				# # Look at the different options for lengths
+				# for partlen in range(2, num_len + 1):
+				# 	# Only continue if it's a factor
+				# 	if num_len % partlen != 0:
+				# 		continue
+				# 	for idx in range(partlen, num_len, partlen): 
+				# 		if num_str[:partlen] == num_str[idx:idx + partlen]:
+				# 			continue
+				# 		palin = True
+				# 		break
+				# if palin:
+				# 	print(num_str, "is a palindrome thing")
+				# 	illegal_counter += 1
+				# 	illegal_sum += num
+
+		print(illegal_counter, illegal_sum)