Palindrome poj-3974 题目大意:求字符串的最长回文子串. 注释:$1\le strlen(s) \le 10^6$. 想法:介绍一种字符串算法——Manacher.求以每一个字符和字符间隔为回文中心的回文半径长度.什么是Manacher? 我们先来考虑这样一种暴力:如果我们用暴力来达到Manacher的效果,我们需要枚举每一个字符以及字符间隔,然后分别向左右扩展更新当前答案,时间复杂度$O(n^2)$,极限数据:连续的同样字符.那么,我们如何对其进行优化? 我们显然不怎么会处理…

https://segmentfault.com/a/1190000008484167?tdsourcetag=s_pctim_aiomsg 讲的超好! manacher算法理解 回文串分为偶回文串和奇回文串,由于偶回文串无法找到中点,所以这里将偶回文串转换为奇回文 转换方法s="abcde"=>s="$#a#b#c#d#e#" 数组p[i],表示以i为中心的最长回文的半径,p[i]-1刚好是以i为中心的源字符串中的回文长度 从左往右扫描s,求出p数组 mx:…

Time Limit: 15000MS   Memory Limit: 65536K Total Submissions: 5121   Accepted: 1834 Description Andy the smart computer science student was attending an algorithms class when the professor asked the students a simple question, "Can you propose an eff…

var s,t:ansistring; n,op:longint; p:..] of longint; procedure pre; var i:longint; begin s:='$*'; to length(t) do begin s:=s+t[i]+'*'; end; s:=s+'#'; n:=length(s); end; function min(a,b:longint):longint; begin if a<b then exit(a) else exit(b); end; pr…

题目大意就是说在给定的字符串里找出一个长度最大的回文子串. 才开始接触到manacher,不过这个算法的确很强大,这里转载了一篇有关manacher算法的讲解,可以去看看:地址 神器: #include <map> #include <set> #include <stack> #include <queue> #include <cmath> #include <ctime> #include <vector> #inc…

http://poj.org/problem?id=3974 Palindrome Time Limit: 15000MSMemory Limit: 65536K Total Submissions: 2707Accepted: 995 Description Andy the smart computer science student was attending an algorithms class when the professor asked the students a simpl…

本文版权归ljh2000和博客园共有,欢迎转载,但须保留此声明,并给出原文链接,谢谢合作. 本文作者:ljh2000 作者博客:http://www.cnblogs.com/ljh2000-jump/转载请注明出处,侵权必究,保留最终解释权! Description Andy the smart computer science student was attending an algorithms class when the professor asked the students a si…

传送门:Palindrome 题意:给定一个字符串,求最长回文子串. 分析:manach裸题,核心理解mx>i?p[i]=min(p[2*id-i],mx-i):1. #pragma comment(linker,"/STACK:1024000000,1024000000") #include <cstdio> #include <cstring> #include <string> #include <cmath> #includ…

Palindrome Time Limit: 15000MS   Memory Limit: 65536K Total Submissions: 3280   Accepted: 1188 Description Andy the smart computer science student was attending an algorithms class when the professor asked the students a simple question, "Can you pro…

链接:点击这里 #include<iostream> #include<algorithm> #include<stdio.h> #include<cstring> using namespace std; #define maxn 1000005 #define LL long long #define ull unsigned long long ; ull p[maxn+],f[maxn],ff[maxn]; int main(){ p[]=; ;j&…