{"id":363,"date":"2012-08-03T18:38:27","date_gmt":"2012-08-03T10:38:27","guid":{"rendered":"http:\/\/www.shuizilong.com\/house\/?p=363"},"modified":"2012-08-04T05:53:33","modified_gmt":"2012-08-03T21:53:33","slug":"spoj-10707-count-on-a-tree-ii","status":"publish","type":"post","link":"https:\/\/www.shuizilong.com\/house\/archives\/spoj-10707-count-on-a-tree-ii\/","title":{"rendered":"SPOJ 10707. Count on a tree II"},"content":{"rendered":"

Brief description: <\/h3>\n

… \u7ed9\u5b9a\u4e00\u68f5\u6811\u70b9\u6743\u6811\uff0c\u6c42\u6811\u4e0a\u4e24\u70b9\u4e4b\u95f4\u7684\u8def\u5f84\u4e0a\uff0c\u51fa\u73b0\u8fc7\u591a\u5c11\u79cd\u4e0d\u540c\u7684\u6743\u503c\u3002
\n
\nTags: \u6811\u4e0a\u83ab\u961f\u7b97\u6cd5\u3001\u4e3b\u5e2d\u7b97\u6cd5<\/p>\n

Analysis: <\/h3>\n

… \u4e3b\u5e2d\u7b97\u6cd5\u592a\u610f\u8bc6\u6d41\u4e86\u3002\u3002\u65e0\u9650\u4ef0\u6155\u3002\u3002\u3002 \/$:Orz \u3002<\/p>\n

\u5148\u5199\u83ab\u961f\u7b97\u6cd5\u5427\u3002\u3002\u51c6\u5907\u5de5\u4f5c\uff0c\u5f00 A\u3001B\u3001C \u4e09\u4e2a\u6570\u7ec4\u3002\u3002\u3002
\n\u3002\u3002A \u6570\u7ec4\u79bb\u6563\u6389\u70b9\u6743\uff0cB \u6570\u7ec4\u5c55\u5f00 dfs \u5e8f\u5217\uff0cC \u6570\u7ec4\u7edf\u8ba1\u6570\u5b57\u5df2\u7ecf\u51fa\u73b0\u4e86\u591a\u5c11\u6b21\u3002\u3002\u3002
\n\u3001\u5148\u4e00\u6b21 dfs() \u5f97\u5230\u5404\u79cd\u5e8f\u5217\u4fe1\u606f\uff0c\u5bf9\u4e8e\u6bcf\u4e2a\u70b9 u\uff0c\u3002\u3002\u3002\u8fdb\u5165\u7684\u65f6\u523b\u5728 B \u6570\u7ec4\u4e2d\u6807\u8bb0 + A[u]\uff0c\u79bb\u5f00\u7684\u65f6\u523b\u6807\u8bb0 – A[u]\u3002\u3002
\n\u3002\u3002\u53e6\u5916\u8bb0\u5f55\u5176\u8fdb\u5165\u7684\u65f6\u523b st[u]\u3002\u3002\uff08\u8fd9\u4e2a\u91cf\u540e\u9762\u6c42 lca \u7684\u65f6\u5019\u4e5f\u8981\u7528\u5230 \u3002\u3002\u3002<\/p>\n

\u3002\u3002\u8fd9\u6837\u5f97\u5230\u4e86\u66b4\u529b\u7b97\u6cd5\u3002\u3002\u3002\u5bf9\u4e8e\u8be2\u95ee (u, v)\uff0c\u53ea\u8981\u4ece st[lca(u, v)] \u65f6\u523b\u5f00\u59cb\uff0c\u5206\u522b\u626b\u63cf\u5230 st[u] \u548c st[v] \u7684\u4f4d\u7f6e\uff0c
\n\u6ce8\u610f lca \u7684\u4f4d\u7f6e\u53ea\u53d6\u4e00\u6b21\u3002\u3002<\/p>\n

\u5148\u628a\u81f3\u6b64\u4e3a\u6b62\u7684\u90e8\u5206\u8c03\u5bf9\u3002\u3002\u4e4b\u540e\u5f00\u59cb\u8c03\u6574\u8be2\u95ee\u987a\u5e8f\u3002\u3002\u3002
\n\u3002\u3002\u6211\u4e00\u5f00\u59cb\u7684\u7b56\u7565\u662f\u6839\u636e lca \u8fdb\u884c\u5206\u7ec4\u3002\u3002\u3002\u4e0d\u8fc7\u8fd9\u4e2a\u9000\u5316\u7684\u592a\u5389\u5bb3\u4e86\u3002\u3002
\n\uff08\u3002\u3002\u8c8c\u4f3c\u662f\u7ec4\u4e0e\u7ec4\u4e4b\u95f4\u7684\u8f6c\u79fb\u6ca1\u5904\u7406\u597d\u3002\u3002\u4e0d\u8fc7\u8fd9\u6837\u5bf9\u4e8e\u4e00\u4e2a\u8be2\u95ee\u3002\u3002\u5c31\u6709\u4e09\u4e2a\u6307\u9488\u4f4d\u7f6e\u3002\u3002\u83ab\u975e\u8981\u8dd1\u4e09\u7ef4\u66fc\u54c8\u987f\u6700\u5c0f\u751f\u6210\u6811\uff1f\u3002\u3002\u3002<\/p>\n

\u3002\u3002\u7136\u540e\u6211\u5c31 yy \u4e86\u4e00\u4e0b\u3002\u3002\u56e0\u4e3a lca \u7684\u4f4d\u7f6e\u4f9d\u8d56\u4e8e u, v\u3002\u3002\u3002Orz\u3002\u3002
\n\u3002\u3002\u3002\u8fd9\u6837\u5c31\u53ea\u5bf9\u540e\u9762\u7684\u4e24\u4e2a\u8f74\u8dd1\u83ab\u961f\u7b97\u6cd5\u3002\u3002\u590d\u6742\u5ea6\u867d\u7136\u4e0d\u592a\u6e05\u695a\u3002\u3002\u4e0d\u8fc7\u597d\u50cf\u80fd\u8fc7\u7684\u6837\u5b50\u3002\u3002\u3002<\/p>\n

\u6811\u4e0a\u83ab\u961f\u7b97\u6cd5\u3002\u3002\uff0830s+ \u3002\u3002\u3002<\/a><\/p>\n

External link: <\/h3>\n

http:\/\/www.spoj.pl\/problems\/COT2\/<\/a>
\nhttp:\/\/seter.is-programmer.com\/posts\/32857.html<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Brief description: … \u7ed9\u5b9a\u4e00\u68f5\u6811\u70b9\u6743\u6811\uff0c\u6c42\u6811\u4e0a\u4e24\u70b9\u4e4b\u95f4\u7684\u8def\u5f84\u4e0a\uff0c\u51fa\u73b0\u8fc7\u591a\u5c11\u79cd\u4e0d\u540c\u7684\u6743\u503c\u3002<\/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":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false}}},"categories":[21],"tags":[24],"class_list":["post-363","post","type-post","status-publish","format-standard","hentry","category-spoj","tag-24"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p2tdP7-5R","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts\/363","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=363"}],"version-history":[{"count":1,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts\/363\/revisions"}],"predecessor-version":[{"id":364,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts\/363\/revisions\/364"}],"wp:attachment":[{"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/media?parent=363"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/categories?post=363"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/tags?post=363"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}