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=1081/a+1/b=1/nですが、b=n+b'と書き換えると n^2がb'で割り切れることが分かる。 従って、n^2が1999個の約数を持つ最小のnを探せばよい。 import Number import Data.List import Data.Maybe descending xs = and . zipWith (>=) xs $ tail xs succ' (n+1) xs = let (ys,z:zs) = splitAt n xs in ys++[z+1]++zs nex… 190 <iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Fjeneshicc.hatenadiary.org%2Fentry%2F20081126%2F1227688041" title="Problem 108 - 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 2008-11-26 17:27:21 rich https://jeneshicc.hatenadiary.org/entry/20081126/1227688041 1.0 100%