palindrome.py

"""
Palindrome for numbers
"""


def palindrome(start: int = 100, finish: int = 999, t_max: bool = False) -> str:
	"""
	Looking for palindrome between multiplication of all numbers in range:
	:start: and :finish: take integers for range
	:t_max: == False - looking for min palindrome
	:t_max: == True - looking for max palindrome
	"""
	# remove negative numbers, also can add isNeg flag to show range with "-"
	# start = -start if start < 0 else start
	# finish = -finish if finish < 0 else finish

	# function is only for absolutes and correct types
	# start * finish == 0 instead of start < 0 or finish < 0
	if type(start) != int or type(finish) != int or start < 0 or finish < 0:
		return "Wrong input"

	# preparing correct range
	start, finish = (start, finish) if finish > start else (finish, start)

	# num for max and min
	final_num = (s_f := 0 if t_max else finish * finish + 1)
	nums = [0, 0]

	for counter, num1 in enumerate(range(start, finish + 1)[::-1] if t_max \
			                               else range(start, finish + 1)):
		# exit for less than max or more than min
		if (num1 * finish < final_num and t_max) or \
				(num1 * start > final_num and not t_max):
			break

		for num2 in (range(start, finish + 1 - counter)[::-1] if t_max else \
				range(start + counter, finish + 1)):
			# exit earlier
			if ((num := num1 * num2) < final_num and t_max) or \
					(num > final_num and not t_max):
				break

			# get palindrome
			if (num_str := str(num)) == num_str[::-1] and \
					((num > final_num and t_max) or \
					 (num < final_num and not t_max)):
				final_num = num
				nums[0], nums[1] = num1, num2

	return f"No palindromes in range {start}-{finish}" \
		if final_num == 0 or final_num == s_f \
		else f"{'Max' if t_max else 'Min'}: {final_num} | {nums[0]}*{nums[1]}"
		

def max_palindrome(start: int = 100, finish: int = 999) -> str:
	"""
	Looking for max palindrome between multiplication of all numbers in range:
	:start: and :finish: take integers for range
	"""
	fin_num = 0
	nums = [0, 0]
	for counter, num1 in enumerate(range(start, finish + 1)[::-1]):
		if num1 * finish < fin_num:
			break
		for num2 in range(start, finish + 1 - counter)[::-1]:
			if (num := num1 * num2) < fin_num:
				break
			if (num_str := str(num)) == num_str[::-1] and num > fin_num:
				fin_num = num
				nums[0], nums[1] = num1, num2

	return f"No palindromes in range {start}-{finish}" if fin_num == 0 else \
			f"{fin_num} | {nums[0]}*{nums[1]}"


if __name__ == "__main__":
	# good results
	print(palindrome(t_max=True))
	print(palindrome())
	print(palindrome(10, 10000, t_max=True))
	print(palindrome(10, 10000))
	# no palindromes
	print(palindrome(15, 16, t_max=True))
	print(palindrome(16, 15))
	# failsafe wrong input
	print(palindrome(-15, -17, t_max=True))
	print(palindrome(-17, 15))
	# max_palindrome function
	print(max_palindrome())