{"id":280,"date":"2026-01-20T02:05:33","date_gmt":"2026-01-19T18:05:33","guid":{"rendered":"https:\/\/liyongquan.cn\/?p=280"},"modified":"2026-01-20T02:06:58","modified_gmt":"2026-01-19T18:06:58","slug":"p5018-noip-2018-%e6%99%ae%e5%8f%8a%e7%bb%84-%e5%af%b9%e7%a7%b0%e4%ba%8c%e5%8f%89%e6%a0%91","status":"publish","type":"post","link":"https:\/\/liyongquan.cn\/?p=280","title":{"rendered":"P5018 [NOIP 2018 \u666e\u53ca\u7ec4] \u5bf9\u79f0\u4e8c\u53c9\u6811"},"content":{"rendered":"\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button\"><a class=\"wp-block-button__link wp-element-button\" href=\"https:\/\/www.luogu.com.cn\/problem\/P5018\" target=\"_blank\" rel=\"noreferrer noopener\">\u9898\u76ee<\/a><\/div>\n<\/div>\n\n\n\n<pre class=\"wp-block-code\"><code>#include&lt;bits\/stdc++.h>\nusing namespace std;\nint n,t;\nstruct tree{\n\tint l,r,v;\n}a&#91;1000001];\nint ans;\nbool pd(int x, int y) {\n\tif (x==-1&amp;&amp;y==-1)\n\t\treturn 1;\n\tif (x==-1||y==-1||a&#91;x].v!=a&#91;y].v)\n\t\treturn 0;\n\treturn pd(a&#91;x].l, a&#91;y].r)&amp;&amp;pd(a&#91;x].r, a&#91;y].l);\n}\nint dp(int x){\n\tif(x==-1)return 0;\n\telse return dp(a&#91;x].l)+dp(a&#91;x].r)+1;\n}\nint main(){\n\tcin>>n;\n\tfor(int i=1;i&lt;=n;i++){\n\t\tcin>>a&#91;i].v;\n\t}\n\tfor(int i=1;i&lt;=n;i++){\n\t\tcin>>a&#91;i].l>>a&#91;i].r;\n\t}\n\tfor(int i=1;i&lt;=n;i++){\n\t\tif(pd(a&#91;i].l,a&#91;i].r))ans=max(ans,dp(i));\n\t}\n\tcout&lt;&lt;ans;\n    return 0;\n}<\/code><\/pre>\n\n\n\n<p>\u770b\u9898\u89e3\u770b\u5230\u7684\u65b9\u6cd5\uff0c\u56e0\u4e3a\u6211\u9012\u5f52\u592a\u70c2\u4e86\uff0c\u76f4\u63a5\u66b4\u529b\u3002<\/p>\n\n\n\n<p>\u5148\u5bf9\u6bcf\u4e2a\u8282\u70b9\u4e3a\u6839\u7684\u5b50\u6811\u8fdb\u884c\u5bf9\u79f0\u5224\u65ad\uff0c\u82e5\u662f\u5bf9\u79f0\u6811\uff0c\u5c31\u8fdb\u884c\u8282\u70b9\u6570\u8ba1\u7b97\uff0c\u6700\u540e\u53d6\u6700\u5927\u5373\u53ef<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u770b\u9898\u89e3\u770b\u5230\u7684\u65b9\u6cd5\uff0c\u56e0\u4e3a\u6211\u9012\u5f52\u592a\u70c2\u4e86\uff0c\u76f4\u63a5\u66b4\u529b\u3002 \u5148\u5bf9\u6bcf\u4e2a\u8282\u70b9\u4e3a\u6839\u7684\u5b50\u6811\u8fdb\u884c\u5bf9\u79f0\u5224\u65ad\uff0c\u82e5\u662f\u5bf9\u79f0\u6811\uff0c\u5c31\u8fdb\u884c\u8282\u70b9\u6570\u8ba1 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[11,10],"class_list":["post-280","post","type-post","status-publish","format-standard","hentry","category-4","tag-11","tag-10"],"_links":{"self":[{"href":"https:\/\/liyongquan.cn\/index.php?rest_route=\/wp\/v2\/posts\/280","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/liyongquan.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/liyongquan.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/liyongquan.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/liyongquan.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=280"}],"version-history":[{"count":1,"href":"https:\/\/liyongquan.cn\/index.php?rest_route=\/wp\/v2\/posts\/280\/revisions"}],"predecessor-version":[{"id":281,"href":"https:\/\/liyongquan.cn\/index.php?rest_route=\/wp\/v2\/posts\/280\/revisions\/281"}],"wp:attachment":[{"href":"https:\/\/liyongquan.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=280"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/liyongquan.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=280"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/liyongquan.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=280"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}