A string s is called an (k,l)-repeat if s is obtained by concatenating k>=1 times some seed string t with length l>=1. For example, the string s = abaabaabaaba is a (4,3)-repeat with t = aba as its seed string. That is, the seed string t is 3 charac…

本篇是罗穗骞<后缀数组——处理字符串的有力工具>的读书笔记. 知识点: 后缀数组.RMQ 解题思路: 枚举长度 \(L\),然后检查长度为 \(L\) 的子串最多能连续重复几次. 对于给定的字符串 \(S\),我们只关注其上坐标为 \(0, L, 2L, ......\) 的点. 如果连续重复子串的首字符恰好在这些点上,那么连续重复子串出现的次数恰好是 \( \frac{lcp(L_1, L_2)}{L} + 1\),(注:\(lcp\) 为 Longest Common Prefix 的简写…

REPEATS - Repeats no tags  A string s is called an (k,l)-repeat if s is obtained by concatenating k>=1 times some seed string t with length l>=1. For example, the string s = abaabaabaaba is a (4,3)-repeat with t = aba as its seed string. That is, th…

题目链接:http://www.spoj.com/problems/REPEATS/en/ 题意:首先定义了一个字符串的重复度.即一个字符串由一个子串重复k次构成.那么最大的k即是该字符串的重复度.现在给定一个长度为n的字符串,求最大重复次数. 思路:根据<<后缀数组——处理字符串的有力工具>>的思路,先穷举长度L,然后求长度为L 的子串最多能连续出现几次.首先连续出现1 次是肯定可以的,所以这里只考虑至少2 次的情况.假设在原字符串中连续出现2 次,记这个子字符串为S,那么S 肯…

[题目链接] http://www.spoj.com/problems/REPEATS/en/ [题目大意] 求重复次数最多的连续重复子串的长度. [题解] 考虑错位匹配,设重复部分长度为l,记s[i]和s[i+l]前缀匹配得到的最长长度为r,枚举所有的l和i,得到r,那么答案就是r/l+1的最大值.计算任意后缀的最长公共前缀可以利用后缀数组+ST表来解决,两个后缀的最长公共前缀就是他们名次之间的h数组的最小值. 显然,枚举i和l的复杂度达到了O(n2),是没有办法完成统计的,我们发现每个区段只…

687. Repeats Problem code: REPEATS A string s is called an (k,l)-repeat if s is obtained by concatenating k>=1 times some seed string t with length l>=1. For example, the string s = abaabaabaaba is a (4,3)-repeat with t = aba as its seed string. Tha…

http://www.spoj.com/problems/REPEATS/ 题意:给一串字符,需要你求这一串字符中有连续重复的字符的重复次数....... 思路:这是和poj3693一种类型的题目......这里是详细解答:http://www.cnblogs.com/ziyi--caolu/p/3193823.html 注意:还需注意的地方,我一直图方便,再求lcp值时,总是从height值的起点到终点,其实应该是起点+1 #include<iostream> #include<std…

REPEATS - Repeats no tags  A string s is called an (k,l)-repeat if s is obtained by concatenating k>=1 times some seed string t with length l>=1. For example, the string s = abaabaabaaba is a (4,3)-repeat with t = aba as its seed string. That is, th…

题目链接:https://vjudge.net/problem/SPOJ-REPEATS REPEATS - Repeats no tags  A string s is called an (k,l)-repeat if s is obtained by concatenating k>=1 times some seed string t with length l>=1. For example, the string s = abaabaabaaba is a (4,3)-repeat…

REPEATS - Repeats 链接:http://www.spoj.com/problems/REPEATS 题意:求S串中某个子串连续循环次数最多的次数. 想法: 从暴力开始,枚举所有串,求出这些串的最小循环节长度,算出连续循环次数. 如何求一个串S的最小循环节长度:即next表示这个串最长后缀与前缀相等的长度,最小循环节长度=S.length-next. KMP可以解决next,于是O(n^2)暴力求出答案.然后优化一下. 上图ans=(len+(x-y))/(x-y). 在SAM一个…