BZOJ2565 longest Double palindrome string

Description sequence and reverse order read the exact same string called Palindrome string. For example, ACBCA is a palindrome string, and ABC is not (ABC's order is "ABC", Reverse is "CBA", not the same).
Enter the string s of length n, to find the longest double palindrome t of S, you can divide t into two parts x, Y, (| x|,| y|≥1) and X and Y are palindrome strings. Input

a line of string s consisting of lowercase English letters.

The output line is an integer representing the length of the longest double palindrome string. Sample InputBaacaabbacabb
Sample Output12
HINT

Sample Description

The string Aacaabbacabb starting from the second character can be divided into two parts, AACAA and Bbacabb, and both are palindrome strings.

For 100% of data, 2≤| S|≤10^5

2015.4.25 New Plus Data group

Source

2012 National Training Team Round 1 day2

The water of Pam, the pros and cons of each position to the left and right of the longest palindrome string length, and then sweep again can be

#include <cstdio>#include<cctype>#include<queue>#include<cstring>#include<algorithm>#defineRep (s,t) for (int i=s;i<=t;i++)#defineren for (int i=first[x];i!=-1;i=next[i])using namespaceStd;inlineintRead () {intx=0, f=1;CharC=GetChar ();  for(;! IsDigit (c); C=getchar ())if(c=='-') f=-1;  for(; IsDigit (c); C=getchar ()) x=x*Ten+c-'0'; returnx*F;}Const intmaxn=100010;CharCH[MAXN];intF2[MAXN],G2[MAXN];structPAM {intCnt,last; intto[maxn][ -],L[MAXN],F[MAXN]; voidinit () {memset (To,0,sizeof(to)); memset (L,0,sizeof(l)); Memset (F,0,sizeof(f)); CNT=f[0]=1; l[1]=-1; last=0; }    voidExtendintCintNintt) {intp=Last ;  while(ch[n]!=ch[n-l[p]-1]) p=F[p]; if(!To[p][c]) {            intnp=++cnt,k=f[p];l[np]=l[p]+2;  while(ch[n]!=ch[n-l[k]-1]) k=F[k]; F[NP]=to[k][c];to[p][c]=NP; } Last=To[p][c]; if(!t) f2[n]=L[last]; Elseg2[n]=L[last]; }}sol;intMain () {scanf ("%s", ch+1);intN=strlen (ch+1), ans=0; Sol.init (); Rep (1, N) sol.extend (ch[i]-'a'I0); Sol.init (); Reverse (Ch+1, ch+n+1); Rep (1, N) sol.extend (ch[i]-'a'I1); Rep (2, N) Ans=max (ans,f2[i-1]+g2[n-i+1]); printf ("%d\n", ans); return 0;}

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BZOJ2565 longest Double palindrome string