{"id":888,"date":"2014-05-13T22:45:13","date_gmt":"2014-05-13T14:45:13","guid":{"rendered":"http:\/\/www.shuizilong.com\/house\/?p=888"},"modified":"2014-05-13T22:50:16","modified_gmt":"2014-05-13T14:50:16","slug":"codeforces-round-245","status":"publish","type":"post","link":"https:\/\/www.shuizilong.com\/house\/archives\/codeforces-round-245\/","title":{"rendered":"Codeforces Round #245"},"content":{"rendered":"

\u4e00\u5957\u672c\u8be5 AK \u7684\u5927\u6c34\u9898\u3002\u3002\u3002\u505a\u6210\u8fd9\u6837\u5b9e\u5728\u662f\u6ca1\u4ec0\u4e48\u597d\u8bf4\u7684\u3002\u3002\u3002 <\/p>\n

Problem E. Points and Segments<\/h2>\n

Brief description: <\/h3>\n

\u3002\u3002\u3002\u7ed9\u5b9a\u4e00\u7ec4 [l, r] \u7ebf\u6bb5\uff0c\u8981\u6c42\u5bf9\u8fd9\u4e9b\u7ebf\u6bb5\u7ea2\u84dd\u67d3\u8272\u3002
\n\u3002\u3002\u4f7f\u5f97\u4efb\u610f\u4e00\u4e2a\u70b9\uff0c\u6240\u8986\u76d6\u5b83\u7684\u7ea2\u84dd\u7ebf\u6bb5\u7684\u5dee\u4e0d\u8d85\u8fc7 1\u3002
\n<\/p>\n

Analysis: <\/h3>\n
\r\n________\r\n  ________\r\n   ________\r\n     ________\r\n       ________ \r\n<\/pre>\n
\u3002\u3002\u3002\u5927\u6982\u80af\u5b9a\u8981\u5bf9\u533a\u95f4\u79bb\u6563\u5316\u3002\u3002\u6240\u4ee5\u5173\u952e\u5c31\u662f\u4e0a\u9762\u8fd9\u79cd\u60c5\u51b5\u3002\u3002\u3002\u3002\u3002\u4e00\u4e2a\u70b9\u88ab\u5f88\u591a\u4e2a\u7ebf\u6bb5\u8986\u76d6\u7684\u60c5\u51b5\u600e\u4e48\u5904\u7406\u3002\u3002\uff1f\u3002
\n\u6211\u4eec\u628a red \u770b\u6210 +1.\u3002\u3002blue \u770b\u6210 -1.\u3002\u3002\u90a3\u4e48 red blue \u4e0d\u5927\u4e8e 1 \u5c31\u662f\u3002\u3002\u3002\u90a3\u4e48\u4e00\u6761\u7ebf\u6bb5\u7684\u67d3\u8272\u53ef\u4ee5\u770b\u6210\u662f\u4e24\u4e2a\u76f8\u53cd\u7684\u524d\u7f00\u64cd\u4f5c\u3002
\n\u3002\u3002\u3002\u8981\u6c42\u4efb\u4f55\u524d\u7f00 abs(S[ ]) \u90fd\u4fdd\u8bc1 <= 1\u3002\u3002\u53c8\u56e0\u4e3a\u64cd\u4f5c\u53ea\u6709 +1 \u548c -1 \u4e24\u79cd\u3002\u3002\u3002\n\u3002\u3002\u3002\u6240\u4ee5 S[even] = 0\u3002\u3002\u3002\u56e0\u6b64\u53ea\u9700\u8981\u5bf9\u3002\u3002\u3002\u6240\u4ee5  2i, 2i+1 \u8fde\u8fb9\u8dd1\u4e8c\u5206\u56fe\u67d3\u8272\u5373\u53ef\u3002\u3002\n\u3002\u3002\u56e0\u4e3a\u8fd9\u79cd\u7ed3\u6784\u603b\u662f\u4e24\u4e24\u6210\u5bf9\u3002\u3002\u4e00\u5bf9\u5728\u5411\u5916\u8fde\u4e00\u6761\u8fb9\u3002\u3002\u56e0\u6b64\u603b\u662f\u5b58\u5728\u89e3\u3002\u3002\u3002\n\n[cpp]\n\/\/}\/* .................................................................................................................................. *\/\n\nconst int N = int(2e5) + 9;\n\nVI adj[N]; int col[N];\nint n;\n\nvoid add_edge(int a, int b){\n    adj[a].PB(b), adj[b].PB(a);\n}\n\n#define v (*it)\n\nvoid dfs(int u, int c = 0){\n    col[u] = c; ECH(it, adj[u]) if (!~col[v]) dfs(v, c^1);\n}\n\nint main(){\n\n#ifndef ONLINE_JUDGE\n    freopen("in.txt", "r", stdin);\n    \/\/freopen("out.txt", "w", stdout);\n#endif\n\n    VII I; REP_C(i, RD(n)){\n        int l, r; RD(l, r); add_edge(i, i+n);\n        I.PB(MP(l, i)), I.PB(MP(r, i+n));\n    }\n    SRT(I); REP(i, n) add_edge(I[i*2].se, I[i*2+1].se);\n    FLC(col, -1); REP(i, n) if(!~col[i]) dfs(i);\n    REP(i, n) OT(col[i]);\n}\n\n[\/cpp]\n\n\n\n
Problem D. Tricky Function<\/h2>\n
Brief description: <\/h3>\n
\u3002\u3002\u3002\u7565\u3002\uff09<\/p>\n
Analysis: <\/h3>\n
\u3002\u3002\u3002\u53ef\u4ee5\u5f53\u6210\u88f8\u6700\u8fd1\u70b9\u5bf9\u3002\u3002\u3002\u3002\u65e0\u5948\u7f51\u4e0a\u6700\u8fd1\u70b9\u5bf9\u9519\u8bef\u4ee3\u7801\u592a\u591a\u3002\uff08\u590d\u6742\u5ea6\u6216\u8005\u5199\u6cd5\uff09\u3002\u3002\u3002\u3002\u3002\u3002
\n\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u6562\u4e0d\u6562\u4e0d\u8fd9\u4e48\u5751\u7239\u3002\u3002\uff01\uff01\u3002\u3002\u3002\u3002<\/p>\n
\r\n\/\/}\/* .................................................................................................................................. *\/\r\n\r\nconst int N = int(1e5) + 9;\r\nVP P; int n;\r\n\r\nbool cmpy(cPo a, cPo b){return a.y < b.y;}\r\n\r\ninline DB cp(VP &P, int l, int r){\r\n    if (l >= r) return OO;\r\n\r\n    int m = (l + r) >> 1; DB d = min(cp(P, l, m), cp(P, m+1, r)), mx = P[m].x;\r\n    inplace_merge(P.begin()+l, P.begin()+m+1, P.begin()+r+1, cmpy);\r\n\r\n    VP t; FOR_1(i, l, r) if (sgn(abs(P[i].x - mx), d)<0) t.PB(P[i]);\r\n    REP(i, SZ(t)) FOR(j, i+1,  min(SZ(t), i+9)) checkMin(d, dist2(t[i], t[j])); \/\/#\r\n    return d;\r\n}\r\n\r\nDB cp(VP& P){\r\n    SRT(P); return cp(P, 0, n-1);\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    DB pre = 0; REP_C(i, RD(n)) P.PB(Po(i, pre += RDD()));\r\n    printf("%.0f\\n" , cp(P)+EPS);\r\n}\r\n<\/pre>\n","protected":false},"excerpt":{"rendered":"
\u4e00\u5957\u672c\u8be5 AK \u7684\u5927\u6c34\u9898\u3002\u3002\u3002\u505a\u6210\u8fd9\u6837\u5b9e\u5728\u662f\u6ca1\u4ec0\u4e48\u597d\u8bf4\u7684\u3002\u3002\u3002 Problem E. Points and Segments Brief description: \u3002\u3002\u3002\u7ed9\u5b9a\u4e00\u7ec4 [l, r] \u7ebf\u6bb5\uff0c\u8981\u6c42\u5bf9\u8fd9\u4e9b\u7ebf\u6bb5\u7ea2\u84dd\u67d3\u8272\u3002 \u3002\u3002\u4f7f\u5f97\u4efb\u610f\u4e00\u4e2a\u70b9\uff0c\u6240\u8986\u76d6\u5b83\u7684\u7ea2\u84dd\u7ebf\u6bb5\u7684\u5dee\u4e0d\u8d85\u8fc7 1\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":[1],"tags":[],"class_list":["post-888","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p2tdP7-ek","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts\/888","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=888"}],"version-history":[{"count":0,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts\/888\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/media?parent=888"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/categories?post=888"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/tags?post=888"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}