Palindromic Substring Time Limit: 10 Seconds      Memory Limit: 65536 KB In the kingdom of string, people like palindromic strings very much. They like only palindromic strings and dislike all other strings. There is a unified formula to calculate th…

Longest Palindromic Substring 回文这种简单的问题,在C里面印象很深啊.希望能一次过. 写的时候才想到有两种情况: 454(奇数位) 4554(偶数位) 第1次提交 class Solution: def longestPalindrome(self, s): """ :type s: str :rtype: str """ print(s) maxPadStr='' # traverse each char l=le…

CA loves strings, especially loves the palindrome strings. One day he gets a string, he wants to know how many palindromic substrings in the substring S[l,r] . Attantion, each same palindromic substring can only be counted once. InputFirst line conta…

CA Loves Palindromic Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others) Total Submission(s): 301    Accepted Submission(s): 131 Problem Description CA loves strings, especially loves the palindrome strings. One day…

回文树,也叫回文自动机,是2014年被西伯利亚民族发明的,其功能如下: 1.求前缀字符串中的本质不同的回文串种类 2.求每个本质不同回文串的个数 3.以下标i为结尾的回文串个数/种类 4.每个本质不同回文串包含的本质不同回文串种类 (本文参考自Palindromic Tree——回文树[处理一类回文串问题的强力工具],Palindromic Tree 回文自动机-回文树 解决回文串的神器) 下面介绍一些数组的意义 next[][]类似于字典树,指向当前字符串在两段同时加上一个字符 fail[]…

回文树 Palindromic Tree 嗯..回文树是个什么东西呢. 回文树(或者说是回文自动机)每个节点代表一个本质不同的回文串. 首先它类似字典树,每个节点有SIGMA个儿子,表示对应的字母. 其次它类似自动机,有一个fail指针,一个节点的fail指针指向这个回文串的最长回文后缀.比如说abbaabba的fail指向abba的最后一个a. 利用回文树,我们可以在线性(不太确定是线性还是\(nlogn\)?)的时间内求出所有本质不同的回文子串,以及以每个字母结尾的最长回文子串. 有一个定理…

KMP,扩展KMP和Manacher就不写了,感觉没多大意思.   之前感觉后缀自动机简直可以解决一切,所以不怎么写后缀数组.   马拉车主要是通过对称中心解决问题,有的时候要通过回文串的边界解决问题,这个时候回文树就用到了,又好写,又强大.   之前整理过一篇后缀自动机的.感觉还要整理一下,顺便把回文树,后缀数组也整理一下 很久没写专题了,如果有空,把回文自动机也学习一下. 一:回文树 前置技能: 马拉车,KMP. 其实也没关系,就是对比一下. 马拉车是利用对称的思想,得到每个点或者空格为对称…

URAL - 1960   Palindromes and Super Abilities 回文树水题,每次插入时统计数量即可. #include<bits/stdc++.h> using namespace std; #define eps 1e-9 #define For(i,a,b) for(int i=a;i<=b;i++) #define Fore(i,a,b) for(int i=a;i>=b;i--) #define lson l,mid,rt<<1 #d…

A string is palindrome, if the string reads the same backward and forward. For example, strings like "a", "aa", "appa", "queryreuq" are all palindromes. For given empty string S, you should process following two que…

19.32% 1000ms 256000K A number is skr, if and only if it's unchanged after being reversed. For example, "12321", "11" and "1" are skr numbers, but "123", "221" are not. FYW has a string of numbers, each su…