def compute(number_of_digits: int = 3) -> int:
"""
A palindromic number reads the same both ways. The largest palindrome made from the product of
two 2-digit numbers is 9009 = 91 × 99.
Find the largest palindrome made from the product of two 3-digit numbers.
Notes:
This is super slow and doesn't skip all the products that have already been computed
in reverse (i.e. won't skip xy if yx has been computed), but gives the right answer
Args:
digits (int, optional): number of digits in product numbers. Defaults to 3.
Returns:
int: largest palindromic product
"""
largest_palindrome = -1
digits = eulerlib.n_digit_numbers(number_of_digits)
for i, j in itertools.product(digits, repeat=2):
k = i * j
if eulerlib.is_palindromic(k):
if k > largest_palindrome:
largest_palindrome = k
return largest_palindrome if largest_palindrome != -1 else None
def problem004(min, max):
max = 0
for i in range(min, max + 1):
for j in range(min, max + 1):
product = i * j
if is_palindromic(product) and product > max:
max = product
return max
def is_lychrel(n, max_iterations):
for i in range(max_iterations):
n += int(str(n)[::-1])
if is_palindromic(n):
return False
return True
