jeneshicc https://blog.hatena.ne.jp/jeneshicc/ 落書き、時々落学 https://jeneshicc.hatenadiary.org/ Project Euler Haskell http://projecteuler.net/index.php?section=problems&id=135 まず、ナイーブな方法。約数を求めて、利用。 import Data.List divisors n = (1,n):d n 2 where d x m | m^2 > x = [] | mod x m == 0 = (m,div x m):d x (m+1) | otherwise = d x (m+1) sol = filter((>0 ).fst).concatMap f.divisors where f (d1,d2) | mod (d1+d2) 4 /= 0 = [] |… 190 <iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Fjeneshicc.hatenadiary.org%2Fentry%2F20081207%2F1228626012" title="Problem 135 - 落書き、時々落学" class="embed-card embed-blogcard" scrolling="no" frameborder="0" style="display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;"></iframe> Hatena Blog https://hatena.blog 2008-12-07 14:00:12 rich https://jeneshicc.hatenadiary.org/entry/20081207/1228626012 1.0 100%