https:\/\/codeforces.com\/contest\/1782\/submission\/189456196<\/a><\/p>\n\r\n#include <lastweapon\/number>\r\nusing namespace lastweapon;\r\nconst int N = int(5e2) + 9;\r\nInt f[N][N], I[2*N], Fact[2*N]; \/\/ i step, min pref sum >= -(j-1)\r\nint n; Int p, q;\r\n\r\nint main() {\r\n\r\n#ifndef ONLINE_JUDGE\r\n freopen("in.txt", "r", stdin);\r\n \/\/freopen("\/Users\/minakokojima\/Documents\/GitHub\/ACM-Training\/Workspace\/out.txt", "w", stdout);\r\n#endif\r\n\r\n MOD = 998244353;\r\n\tRD(n); p = Int(RD()) \/ 10000; q = Int(1) - p;\r\n\tfor (int i=(I[1]=1)+1; i<=2*n; i++) I[i] = 1ll * (MOD - MOD \/ i) * I[MOD%i] % MOD;\r\n\tFact[0] = 1; REP_1(i, n) Fact[i] = Fact[i-1] * i;\r\n\r\n\tREP_1(i, n+1) f[0][i] = 1;\r\n\r\n\t\/\/ \\sum f[a] * (p*f[b]+q*f[b]) * \\binom{i}{a, b+1}\r\n\tREP_1(i, n) REP_1(j, n-i+1) {\r\n REP(a, i) {\r\n int b = i-1-a;\r\n f[i][j] += f[a][j] * (p*f[b][j+1] + q*f[b][j-1]) * I[b+1];\r\n }\r\n\t}\r\n\r\n Int z = f[n][1] * Fact[n]; REP_1(i, n) {\r\n z *= I[i*2-1];\r\n }\r\n cout << z << endl;\r\n}\r\n\r\n<\/pre>\n","protected":false},"excerpt":{"rendered":"\u53c8\u662f\u4e45\u8fdd\u7684 tourist round\u3002\u3002\u3002 Problem D. https:\/\/zhuanlan.zhihu.com\/p\/599333683 Problem F – Bracket Insertion \u9898\u610f \u6784\u9020\u4e00\u4e2a\u521d\u59cb\u4e3a\u7a7a\u7684\u62ec\u53f7\u5e8f\u5217\uff0c\u6267\u884c n \u6b21\u63d2\u5165\u64cd\u4f5c\uff0c\u6bcf\u6b21\u64cd\u4f5c\u4efb\u9009\u5e8f\u5217\u4e2d\u7684\u4e00\u4e2a\u4f4d\u7f6e\uff0c\u63d2\u5165 “()” \u6216 “)(“\u3002 \u95ee\u6700\u7ec8\u6784\u6210\u7684\u62ec\u53f7\u5e8f\u5217\u4e3a\u5408\u6cd5\u62ec\u53f7\u5e8f\u5217\u7684\u64cd\u4f5c\u65b9\u6848\u7684\u6982\u7387\u3002 \u9898\u89e3 \u7ec4\u5408\u8ba1\u6570\u3002 \u5148\u8f6c\u6362\u6210\u8ba1\u6570\u95ee\u9898\uff0c\u4e0d\u96be\u53d1\u73b0\uff0c\u5bf9\u4e8e\u7b2c i \u6b21\u64cd\u4f5c\uff0c\u6211\u4eec\u6709 i*2-1 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[…]<\/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-2143","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p2tdP7-yz","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts\/2143","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=2143"}],"version-history":[{"count":28,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts\/2143\/revisions"}],"predecessor-version":[{"id":2171,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts\/2143\/revisions\/2171"}],"wp:attachment":[{"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/media?parent=2143"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/categories?post=2143"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/tags?post=2143"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}