{"url":"https://obelisk.hatenablog.com/entry/2016/01/30/013016","height":"190","version":"1.0","provider_name":"Hatena Blog","title":"\u884c\u5217\u306e\u7a4d","blog_url":"https://obelisk.hatenablog.com/","width":"100%","author_name":"obelisk2","provider_url":"https://hatena.blog","categories":["Ruby"],"blog_title":"Camera Obscura","published":"2016-01-30 01:30:16","author_url":"https://blog.hatena.ne.jp/obelisk2/","description":"class Array def mul(x) m = self.size - 1 n = x.size - 1 c = Array.new(m + 1) c.each_index {|i| c[i] = Array.new(m + 1, 0)} for i in 0..m for j in 0..m for k in 0..n c[i][j] += self[i][k] * x[k][j] end end end c end end a = [[-1, -1, 2], [-1, 2, -1], [2, -1, -1]] b = [[2, -1, 0], [-1, 2, -1], [0, -1,\u2026","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fobelisk.hatenablog.com%2Fentry%2F2016%2F01%2F30%2F013016\" title=\"\u884c\u5217\u306e\u7a4d - Camera Obscura\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","image_url":null,"type":"rich"}