Python/project_euler/problem_36/sol1.py
Nelson Stoik 1c0deb88ac
Coding style change for project_euler problem 36 and 35 (#3062)
* add problem url. Add typehint, default value and doctest

* run black

* add project url. add solution function for problem 35

* add space between imports on problem 35

* Update sol1.py

* Update sol1.py

Co-authored-by: Dhruv <dhruvmanila@gmail.com>
2020-10-09 08:35:13 +05:30

70 lines
1.4 KiB
Python

"""
Project Euler Problem 36
https://projecteuler.net/problem=36
Problem Statement:
Double-base palindromes
Problem 36
The decimal number, 585 = 10010010012 (binary), is palindromic in both bases.
Find the sum of all numbers, less than one million, which are palindromic in
base 10 and base 2.
(Please note that the palindromic number, in either base, may not include
leading zeros.)
"""
from typing import Union
def is_palindrome(n: Union[int, str]) -> bool:
"""
Return true if the input n is a palindrome.
Otherwise return false. n can be an integer or a string.
>>> is_palindrome(909)
True
>>> is_palindrome(908)
False
>>> is_palindrome('10101')
True
>>> is_palindrome('10111')
False
"""
n = str(n)
return True if n == n[::-1] else False
def solution(n: int = 1000000):
"""Return the sum of all numbers, less than n , which are palindromic in
base 10 and base 2.
>>> solution(1000000)
872187
>>> solution(500000)
286602
>>> solution(100000)
286602
>>> solution(1000)
1772
>>> solution(100)
157
>>> solution(10)
25
>>> solution(2)
1
>>> solution(1)
0
"""
total = 0
for i in range(1, n):
if is_palindrome(i) and is_palindrome(bin(i).split("b")[1]):
total += i
return total
if __name__ == "__main__":
print(solution(int(str(input().strip()))))