{"description":"\u968e\u4e57\uff08Factorial\uff09 \u203b3! = 3*2*1 \u203b0!\u306f1 // factorial n! public static long factorial(int n) { if (n<=1) return 1; else return n * factorial(n-1); } \u9806\u5217\uff08Permutation\uff09\uff1a\u4e26\u3079\u308b\u9806\u756a\u3092\u533a\u5225\u3059\u308b nPm = n!/(n-m)! \u8a3c\u660e\uff09abcde\u304b\u3089\uff13\u3064\u53d6\u3063\u3066\u4e00\u5217\u306b\u4e26\u3079\u308b n=5,m=3 5*4*3 = 5!/2! = 5!/(5-3)!\u4f8b\uff09abc\u3092\u4e00\u5217\u306b\u4e26\u3079\u308b\uff08\uff1d\u3064\u307e\u308aabc\u304b\u3089\u4e09\u500b\u3068\u3063\u3066\u4e00\u5217\u306b\u4e26\u3079\u308b\uff09 3*2*1 = 3! = 3!/(3-3)! \u7d44\u5408\u305b\uff08\u2026","height":"190","author_url":"https://blog.hatena.ne.jp/ykmbpp/","published":"2008-07-26 04:28:50","type":"rich","url":"https://ykmbpp.hatenadiary.org/entry/20080726/1217100530","author_name":"ykmbpp","width":"100%","blog_url":"https://ykmbpp.hatenadiary.org/","image_url":null,"version":"1.0","provider_name":"Hatena Blog","title":"\u968e\u4e57\u30fb\u9806\u5217\u30fb\u7d44\u5408\u305b","categories":["\u6570\u5b66\u306e\u518d\u52c9\u5f37"],"html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fykmbpp.hatenadiary.org%2Fentry%2F20080726%2F1217100530\" title=\"\u968e\u4e57\u30fb\u9806\u5217\u30fb\u7d44\u5408\u305b - YKMbPP\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","blog_title":"YKMbPP","provider_url":"https://hatena.blog"}