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Digit sum of 100!
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Michael F. Stemper
Aug 21, 2022, 2:17:49 PM8/21/22
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I've recently started working my way through Project Euler[1].
So far, I've had to think, but none of the problems have been
insurmountable.
In fact, I've just encountered the opposite with Problem 20[2].
This problem calls for finding the sum of the digits of 100!
(implicitly its decimal representation).
A python one-liner can calculate 100!, convert it to a string,
and sum the values of the characters in that string. Easy-peasy!
However, this is a brute-force approach, and I don't think that's
what this challenge is all about. Is there some fact about factorials
that I should be using? Can somebody give me a hint that will
seem blindingly obvious once I read it?
I absolutely do not want the answer, just a general pointer.
Thanks.
[1] <https://projecteuler.net/>
[2] <https://projecteuler.net/problem=20>
--
Michael F. Stemper
Always remember that you are unique. Just like everyone else.
So far, I've had to think, but none of the problems have been
insurmountable.
In fact, I've just encountered the opposite with Problem 20[2].
This problem calls for finding the sum of the digits of 100!
(implicitly its decimal representation).
A python one-liner can calculate 100!, convert it to a string,
and sum the values of the characters in that string. Easy-peasy!
However, this is a brute-force approach, and I don't think that's
what this challenge is all about. Is there some fact about factorials
that I should be using? Can somebody give me a hint that will
seem blindingly obvious once I read it?
I absolutely do not want the answer, just a general pointer.
Thanks.
[1] <https://projecteuler.net/>
[2] <https://projecteuler.net/problem=20>
--
Michael F. Stemper
Always remember that you are unique. Just like everyone else.
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