{"description":"\u3078\u3048\u3002\u4e0b\u964d\u968e\u4e57\u51aa\u3063\u3066\u3044\u3046\u306e\u304c\u3042\u308b\u306e\u304b\u3002\u3069\u3063\u3061\u3067\u3082\u3044\u3044\u3051\u3069\u3002 class Fact ... def falling(m, n) self[m].div(self[m - n]) end end def nCm(n, m) fact = Fact.new fact.falling(n, m).div(fact.falling(m, m)) end p nCm(30, 7)","blog_title":"@m_seki \u306e","version":"1.0","published":"2007-09-19 01:09:56","provider_url":"https://hatena.blog","type":"rich","author_name":"m_seki","author_url":"https://blog.hatena.ne.jp/m_seki/","url":"https://druby.hatenablog.com/entry/20070919/1190131796","blog_url":"https://druby.hatenablog.com/","width":"100%","title":" \u4e0b\u964d\u968e\u4e57\u51aa","provider_name":"Hatena Blog","categories":[],"image_url":null,"height":"190","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fdruby.hatenablog.com%2Fentry%2F20070919%2F1190131796\" title=\" \u4e0b\u964d\u968e\u4e57\u51aa - @m_seki \u306e\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>"}