{"id":99,"date":"2010-09-16T08:20:58","date_gmt":"2010-09-16T00:20:58","guid":{"rendered":"http:\/\/www.shuizilong.com\/house\/?p=99"},"modified":"2012-03-03T08:21:11","modified_gmt":"2012-03-03T00:21:11","slug":"poj-1743-musical-theme","status":"publish","type":"post","link":"https:\/\/www.shuizilong.com\/house\/archives\/poj-1743-musical-theme\/","title":{"rendered":"POJ 1743. Musical Theme"},"content":{"rendered":"<h3>Brief description :<\/h3>\n<p>\u540e\u7f00\u6570\u7ec4\u7ec3\u4e60\u9898\u7cfb\u5217\u554a\u554a\uff0c\u6700\u957f\u4e0d\u91cd\u53e0\u91cd\u590d\u5b50\u4e32\u3002<br \/>\n<!--more--><\/p>\n<h3>Analyse :<\/h3>\n<p>&#8230; <\/p>\n<pre lang=\"cpp\" file=\"POJ_1743.cpp\">\r\n\/*\t\r\n\tAuthor : xiaodao\r\n\tProb : POJ 1743. Musical Theme\r\n\tStatus  : Accepted\r\n\tLast modify : GMT +8. Sept 16th 11:07\r\n\tTags : Suffix Array\r\n*\/\r\n\r\n#include <iostream>\r\n#include <cstdio>\r\n#include <cstring>\r\n#include <string>\r\nusing namespace std;\r\n\r\nconst int INF = 100000;\r\nconst int N = 20000, M = 88;\r\nint SA[N], rank[N], height[N], key[N];\r\nint A[N], C[N], t1[N+1], t2[N+1];\r\nint n, m, ans;\r\n\r\nvoid init(){\r\n\tint i, j, k, l, s; int *X = t1, *Y = t2; \r\n\tfor (i=0;i<n;i++) scanf(\"%d\", &#038;A[i]); n--; s = 0;\r\n\tfor (i=0;i<n;i++) A[i] = A[i+1] - A[i], s = min(s, A[i]);\r\n\tfor (i=0;i<n;i++) A[i] -= s;\r\n\t\r\n\tm = M * 2;\r\n\t\r\n\tmemset(C, 0, sizeof(C));\r\n\tfor (i=0;i<n;i++) C[X[i] = A[i]]++;\r\n\tfor (i=1;i<m;i++) C[i] += C[i-1];\r\n\tfor (i=n-1;i>=0;i--) SA[--C[X[i]]] = i;\r\n\t\r\n\tX[n] = Y[n] = INF;\r\n\t\r\n\tfor (l=1;l<n;l<<=1){\r\n\t\tfor (i=n-l,j=0;i<n;i++) Y[j++] = i;\r\n\t\tfor (i=0;i<n;i++) if (SA[i] >= l) Y[j++] = SA[i] - l;\r\n\t\tfor (i=0;i<n;i++) key[i] = X[Y[i]];\r\n\t\t\r\n\t\tmemset(C, 0, sizeof(C));\r\n\t\tfor (i=0;i<n;i++) C[key[i]]++;\r\n\t\tfor (i=1;i<m;i++) C[i] += C[i-1];\r\n\t\tfor (i=n-1;i>=0;i--) SA[--C[key[i]]] = Y[i];\r\n\t\t\r\n\t\tswap(X, Y);\r\n\t\tX[SA[0]] = j = 0;\r\n\t\tfor (i=1;i<n;i++){\r\n\t\t\tif (Y[SA[i]] != Y[SA[i-1]] || Y[SA[i]+l] != Y[SA[i-1]+l])\r\n\t\t\t\tj++;\r\n\t\t\tX[SA[i]] = j;\r\n\t\t}\r\n\t\tm = j + 1;\r\n\t\tif (m==n) break;\r\n\t}\r\n\t\r\n\tfor (i=0;i<n;i++)\r\n\t\trank[SA[i]] = i;\r\n\t\r\n\tk = 0;\r\n\tfor (i=0;i<n;i++){\r\n\t\tif (k>0) k--;\r\n\t\tif (rank[i]==0) height[0] = 0;\r\n\t\telse {\r\n\t\t\tj = SA[rank[i] - 1];\r\n\t\t\twhile (A[i+k]==A[j+k]) k++;\r\n\t\t\theight[rank[i]] = k;\r\n\t\t}\r\n\t} \r\n}\r\n\r\nbool f(int x){\r\n\tint l = SA[0], r = SA[0];\r\n\tfor (int i=1;i<n;i++){\r\n\t\tif (height[i] >= x) l = min(l, SA[i]), r = max(r, SA[i]);\r\n\t\telse {\r\n\t\t\tif (r-l >= x) return true;\r\n\t\t\tl = SA[i], r = SA[i];\r\n\t\t}\r\n\t}\r\n\t\r\n\tif (r-l >= x) return true;\r\n\treturn false;\r\n}\r\n\r\n\r\nvoid solve(){\r\n\t\r\n\tif (!f(4)) ans = 0;\r\n\telse {\r\n\t\tint l=4, r=n\/2, m;\r\n\t\twhile (l<r){\r\n\t\t\tm = (l+r+1) \/ 2;\r\n\t\t\tif (f(m)) l = m;\r\n\t\t\telse r = m - 1;\r\n\t\t}\r\n\t\tans = l + 1;\r\n\t}\r\n}\r\n\r\nint main(){\r\n\t\/\/freopen(\"in.txt\", \"r\", stdin);\r\n\twhile (cin>>n && n!=0){\r\n\t\tinit(); solve();\r\n\t\tcout << ans << endl;\r\n\t}\t\r\n}\r\n<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Brief description : \u540e\u7f00\u6570\u7ec4\u7ec3\u4e60\u9898\u7cfb\u5217\u554a\u554a\uff0c\u6700\u957f\u4e0d\u91cd\u53e0\u91cd\u590d\u5b50\u4e32\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-99","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p2tdP7-1B","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts\/99","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=99"}],"version-history":[{"count":0,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/posts\/99\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/media?parent=99"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/categories?post=99"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.shuizilong.com\/house\/wp-json\/wp\/v2\/tags?post=99"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}