{"id":3043,"date":"2023-06-23T01:42:20","date_gmt":"2023-06-22T17:42:20","guid":{"rendered":"https:\/\/www.shuizilong.com\/house\/?p=3043"},"modified":"2023-06-23T01:42:20","modified_gmt":"2023-06-22T17:42:20","slug":"luogu-p2179-noi2012-%e9%aa%91%e8%a1%8c%e5%b7%9d%e8%97%8f","status":"publish","type":"post","link":"https:\/\/www.shuizilong.com\/house\/archives\/luogu-p2179-noi2012-%e9%aa%91%e8%a1%8c%e5%b7%9d%e8%97%8f\/","title":{"rendered":"Luogu P2179. [NOI2012] \u9a91\u884c\u5ddd\u85cf"},"content":{"rendered":"<ul>\n<li><a href=\"https:\/\/www.luogu.com.cn\/problem\/P2179\">https:\/\/www.luogu.com.cn\/problem\/P2179<\/a><\/li>\n<\/ul>\n<p>\u6700\u4f18\u89e3\u60c5\u51b5\u4e0b\u6bcf\u4e2a\u5206\u91cf\u7684\u5bfc\u6570\u76f8\u540c\uff0c\u4e8c\u5206\u8fd9\u4e2a\u5bfc\u6570\u5373\u53ef\u3002<\/p>\n<pre class=\"brush: cpp; light: false; title: ; toolbar: true; notranslate\" title=\"\">\r\n#include &lt;lastweapon\/io&gt;\r\nusing namespace lastweapon;\r\n\r\nconst int N = int(1e4) + 9;\r\nint n;\r\ndouble e, s&#x5B;N], k&#x5B;N], u&#x5B;N];\r\n\r\ndouble calcV(double x, int i) {\r\n    double l = 0, r = INF, mid;\r\n    int cnt = 233;\r\n    while(cnt--) {\r\n        mid = (l+r)\/2;\r\n        if(2*k&#x5B;i]*s&#x5B;i]*mid*mid*(mid-u&#x5B;i])*x &gt; -s&#x5B;i]) l = mid ;else r = mid;\r\n    }\r\n    return (l+r)\/2;\r\n}\r\n\r\ndouble calcE(double x) {\r\n    double res = 0;\r\n    REP(i, n) {\r\n        double v = calcV(x, i);\r\n        res += k&#x5B;i]*(v-u&#x5B;i])*(v-u&#x5B;i])*s&#x5B;i];\r\n    }\r\n    return res;\r\n}\r\n\r\nint main() {\r\n\r\n#ifndef ONLINE_JUDGE\r\n    freopen(&quot;in.txt&quot;, &quot;r&quot;, stdin);\r\n    \/\/freopen(&quot;out.txt&quot;, &quot;w&quot;, stdout);\r\n#endif\r\n\r\n    RD(n);\r\n    RF(e);\r\n    REP(i, n) RF(s&#x5B;i], k&#x5B;i], u&#x5B;i]);\r\n    double l = -INF, r = 0, mid;\r\n    DO(100){\r\n        mid = (l+r)\/2;\r\n        if(calcE(mid) &lt;= e) l = mid ;else r = mid;\r\n    }\r\n    mid = (l+r)\/2;\r\n    double ans = 0;\r\n    REP(i, n) ans += s&#x5B;i] \/ calcV(mid, i);\r\n    printf(&quot;%.6lf&quot;, ans);\r\n}\r\n<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>https:\/\/www.luogu.com.cn\/problem\/P2179 \u6700\u4f18\u89e3\u60c5\u51b5\u4e0b\u6bcf\u4e2a\u5206\u91cf\u7684\u5bfc\u6570\u76f8\u540c\uff0c\u4e8c\u5206\u8fd9\u4e2a\u5bfc\u6570\u5373\u53ef\u3002 #include &lt;lastweapon\/io&gt; using namespace lastweapon; const int N = int(1e4) + 9; int n; double e, s&#x5B;N], k&#x5B;N], u&#x5B;N]; double calcV(double x, int i) { double l = 0, r = INF, mid; int cnt = 233; while(cnt&#8211;) { mid = (l+r)\/2; if(2*k&#x5B;i]*s&#x5B;i]*mid*mid*(mid-u&#x5B;i])*x &gt; -s&#x5B;i]) l = mid ;else r = mid; } [&hellip;]<\/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-3043","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p2tdP7-N5","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts\/3043","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=3043"}],"version-history":[{"count":1,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts\/3043\/revisions"}],"predecessor-version":[{"id":3044,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts\/3043\/revisions\/3044"}],"wp:attachment":[{"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/media?parent=3043"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/categories?post=3043"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/tags?post=3043"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}