Python/project_euler/problem_004/sol2.py
Maxim Smolskiy 4700297b3e
Enable ruff RUF002 rule (#11377)
* Enable ruff RUF002 rule

* Fix

---------

Co-authored-by: Christian Clauss <cclauss@me.com>
2024-04-22 21:51:47 +02:00

40 lines
1001 B
Python

"""
Project Euler Problem 4: https://projecteuler.net/problem=4
Largest palindrome product
A palindromic number reads the same both ways. The largest palindrome made
from the product of two 2-digit numbers is 9009 = 91 x 99.
Find the largest palindrome made from the product of two 3-digit numbers.
References:
- https://en.wikipedia.org/wiki/Palindromic_number
"""
def solution(n: int = 998001) -> int:
"""
Returns the largest palindrome made from the product of two 3-digit
numbers which is less than n.
>>> solution(20000)
19591
>>> solution(30000)
29992
>>> solution(40000)
39893
"""
answer = 0
for i in range(999, 99, -1): # 3 digit numbers range from 999 down to 100
for j in range(999, 99, -1):
product_string = str(i * j)
if product_string == product_string[::-1] and i * j < n:
answer = max(answer, i * j)
return answer
if __name__ == "__main__":
print(f"{solution() = }")