inamori https://blog.hatena.ne.jp/inamori/ inamori’s diary https://inamori.hateblo.jp/ Haskell Problem 45 http://projecteuler.net/index.php?section=problems&id=45 六角数は三角数なので、三角数は無視できる。五角数と六角数を並べて比較していくだけ。 polygonal p = [ div (n * ((p - 2) * n - (p - 4))) 2 | n equal (p:ps) (h:hs) | p == h = [p] ++ (equal ps hs) | p | p > h = equal (p:ps) hs main = print(last (take 3 (equal (polygonal 5) (poly… 190 <iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Finamori.hateblo.jp%2Fentry%2F20100215%2Fp2" title="Project Euler 45,46 - inamori’s diary" 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 2010-02-15 00:00:01 rich https://inamori.hateblo.jp/entry/20100215/p2 1.0 100%