{"categories":["Haskell"],"author_url":"https://blog.hatena.ne.jp/shigemk2/","provider_name":"Hatena Blog","image_url":"http://ecx.images-amazon.com/images/I/51P6NdS4IGL.jpg","height":"190","description":"readhbon.doorkeeper.jp do\u8a18\u6cd5 do\u3092\u4f7f\u3046\u30d1\u30bf\u30fc\u30f3\u3068\u4f7f\u308f\u306a\u3044\u30d1\u30bf\u30fc\u30f3\u3067\u6bd4\u3079\u3066\u307f\u308b\u3002 type Birds = Int type Pole = (Birds, Birds) -- \u9ce5 landLeft :: Birds -> Pole -> Maybe Pole landLeft n (left, right) | abs ((left + n) - right) < 4 = Just (left + n, right) | otherwise = Nothing landRight :: Birds -> Pole -> Maybe Pole landRight n (\u2026","author_name":"shigemk2","width":"100%","blog_title":"by shigemk2","published":"2015-09-30 21:38:26","version":"1.0","title":"\u7b2c2\u671f \u7b2c22\u56de H\u672c\u8aad\u66f8\u4f1a in \u79cb\u8449\u539f #readhbon","blog_url":"https://www.shigemk2.com/","url":"https://www.shigemk2.com/entry/readhbon22","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fwww.shigemk2.com%2Fentry%2Freadhbon22\" title=\"\u7b2c2\u671f \u7b2c22\u56de H\u672c\u8aad\u66f8\u4f1a in \u79cb\u8449\u539f #readhbon - by shigemk2\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","type":"rich","provider_url":"https://hatena.blog"}