05 [TEMPLATE] manacher algorithm, p3805manacher Algorithm

05 [TEMPLATE] manacher algorithm, p3805manacher Algorithm
Description

Returns the length of a string consisting of lowercase letters a, B, c... y, and z.

String Length: n

Input/Output Format

Input Format:

 

A string consisting of lowercase letters a, B, c... y, and z.

 

Output Format:

 

An integer indicates the answer.

 

Input and Output sample input sample #1:

aaa

Output sample #1:

3

Description

String Length len <= 11000000

 

Manacher of Lu Jiao is too low ,,

Write one T,

The bitwise computation type will be changed later.

Only 300 ms at one point

 

 1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<cmath> 5 #include<queue> 6 #include<algorithm> 7 #include<cstdlib> 8 #define lli long long int  9 using namespace std;10 const lli MAXN=31000011;11 char s[MAXN];12 char str[MAXN];13 int ans[MAXN];14 int len=0;15 int ls=0;16 void getstr()17 {18     str[0]='#';19     str[1]='#';20     for(int i=0;i<ls;i++)21     str[(i<<1)+2]=s[i],str[(i<<1)+3]='#';22     ls=(ls<<1)+2;23     str[ls]=0;24 }25 void manacher()26 {27     getstr();28     int mx=0,id=0;29     30     len=strlen(str);31     for(int i=1;i<len;i++)32     {33         if(mx>i)34             ans[i]=min(ans[2*id-i],mx-i);35         else ans[i]=1;36         while(str[i+ans[i]]==str[i-ans[i]])37             ++ans[i];38         if(i+ans[i]>mx)39             mx=i+ans[i],id=i;40             41     }42 }43 int main()44 {45     scanf("%s",s);46     ls=strlen(s);47     manacher();48     int out=0;49     for(int i=0;i<len;i++)50         out=max(out,ans[i]);51     printf("%d",out-1);52     return 0;53 }