SGU 282. Isomorphism<\/a> \u4e00\u6837\u3002<\/p>\n\r\n#include <lastweapon\/number>\r\n\r\nusing namespace lastweapon;\r\n\r\nconst int N = int(5e1) + 9;\r\nInt Fact[N]; VVI Partition; VI cur;\r\nint n;\r\n\r\nvoid gen(int n = ::n, int s = 1){\r\n if (!n){\r\n Partition.PB(cur);\r\n }\r\n else if (n >= s){\r\n cur.PB(s); gen(n-s, s); cur.pop_back();\r\n gen(n, s+1);\r\n }\r\n}\r\n\r\nInt c(const VI P){\r\n\r\n Int z = Fact[n]; int c = 0, l = P.front();\r\n\r\n ECH(it, P){\r\n z \/= *it; if (*it != l){\r\n z \/= Fact[c]; l = *it;\r\n c = 1;\r\n }\r\n else{\r\n ++c;\r\n }\r\n }\r\n\r\n z \/= Fact[c];\r\n return z;\r\n}\r\n\r\nVII adj[N];\r\nint w[N]; bool vis[N];\r\nint sw, sz;\r\n\r\nvoid dfs(int u) {\r\n vis[u] = 1;\r\n sw += w[u]; sz += 1;\r\n for (auto e: adj[u]) {\r\n int v = e.fi; \/\/w = e.se;\r\n if (!vis[v]) dfs(v);\r\n }\r\n}\r\n\r\nint g(const VI P){\r\n\r\n REP(i, SZ(P)) {\r\n w[i] = 0; vis[i] = 0;\r\n adj[i].clear();\r\n }\r\n\r\n int z = 0; REP(i, SZ(P)){\r\n z += (P[i] - 1) \/ 2;\r\n if (!(P[i]&1)) w[i] += 1;\r\n\r\n REP(j, i) {\r\n int d = __gcd(P[i], P[j]);\r\n int ei = P[j] \/ d, ej = P[i] \/ d;\r\n if (ei&1) {\r\n if (ej&1) {\r\n adj[i].PB({j,0});\r\n adj[j].PB({i,0});\r\n z += d;\r\n } else {\r\n w[i] += d;\r\n }\r\n } else {\r\n if (ej&1) {\r\n w[j] += d;\r\n } else {\r\n z += d;\r\n }\r\n }\r\n }\r\n }\r\n\r\n REP(i, SZ(P)) if (!vis[i]){\r\n sw = 0; sz = 0; dfs(i);\r\n z += max(sw-1, 0) - (sz-1);\r\n }\r\n return z;\r\n}\r\n\r\nint main(){\r\n\r\n#ifndef ONLINE_JUDGE\r\n \/\/freopen("in.txt", "r", stdin);\r\n \/\/freopen("out.txt", "w", stdout);\r\n#endif\r\n\r\n MOD = 998244353;\r\n\r\n RD(n); Fact[0] = 1; REP_1(i, n) Fact[i] = Fact[i-1] * i;\r\n\r\n gen();\r\n\r\n Int res = 0; ECH(it, Partition){\r\n res += c(*it) * pow(Int(2), g(*it));\r\n }\r\n res \/= Fact[n];\r\n cout << res << endl;\r\n}\r\n<\/pre>\n","protected":false},"excerpt":{"rendered":"\u9898\u610f \u65e0\u6807\u53f7\u6b27\u62c9\u56fe\u8ba1\u6570 \u5206\u6790 \u505a\u6cd5\u57fa\u672c\u548c SGU 282. Isomorphism \u4e00\u6837\u3002 #include <lastweapon\/number> using namespace lastweapon; const int N = int(5e1) + 9; Int Fact[N]; VVI Partition; VI cur; int n; void gen(int n = ::n, int s = 1){ if (!n){ Partition.PB(cur); } else if (n >= s){ cur.PB(s); gen(n-s, s); cur.pop_back(); gen(n, s+1); } } Int […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false}}},"categories":[1],"tags":[],"class_list":["post-2875","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p2tdP7-Kn","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts\/2875","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/comments?post=2875"}],"version-history":[{"count":1,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts\/2875\/revisions"}],"predecessor-version":[{"id":2876,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts\/2875\/revisions\/2876"}],"wp:attachment":[{"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/media?parent=2875"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/categories?post=2875"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/tags?post=2875"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}