Python/project_euler/problem_043/sol1.py
Dhruv 44254cf112
Rename Project Euler directories and other dependent changes (#3300)
* Rename all Project Euler directories:

Reason:
The change was done to maintain consistency throughout the directory
and to keep all directories in sorted order.

Due to the above change, some config files had to be modified:
'problem_22` -> `problem_022`

* Update scripts to pad zeroes in PE directories
2020-10-15 12:43:28 +05:30

61 lines
1.6 KiB
Python

"""
Problem 43: https://projecteuler.net/problem=43
The number, 1406357289, is a 0 to 9 pandigital number because it is made up of
each of the digits 0 to 9 in some order, but it also has a rather interesting
sub-string divisibility property.
Let d1 be the 1st digit, d2 be the 2nd digit, and so on. In this way, we note
the following:
d2d3d4=406 is divisible by 2
d3d4d5=063 is divisible by 3
d4d5d6=635 is divisible by 5
d5d6d7=357 is divisible by 7
d6d7d8=572 is divisible by 11
d7d8d9=728 is divisible by 13
d8d9d10=289 is divisible by 17
Find the sum of all 0 to 9 pandigital numbers with this property.
"""
from itertools import permutations
def is_substring_divisible(num: tuple) -> bool:
"""
Returns True if the pandigital number passes
all the divisibility tests.
>>> is_substring_divisible((0, 1, 2, 4, 6, 5, 7, 3, 8, 9))
False
>>> is_substring_divisible((5, 1, 2, 4, 6, 0, 7, 8, 3, 9))
False
>>> is_substring_divisible((1, 4, 0, 6, 3, 5, 7, 2, 8, 9))
True
"""
tests = [2, 3, 5, 7, 11, 13, 17]
for i, test in enumerate(tests):
if (num[i + 1] * 100 + num[i + 2] * 10 + num[i + 3]) % test != 0:
return False
return True
def solution(n: int = 10) -> int:
"""
Returns the sum of all pandigital numbers which pass the
divisiility tests.
>>> solution(10)
16695334890
"""
list_nums = [
int("".join(map(str, num)))
for num in permutations(range(n))
if is_substring_divisible(num)
]
return sum(list_nums)
if __name__ == "__main__":
print(f"{solution() = }")