Codeforces Beta Round #7 D. Palindrome Degree —— 字符串哈希

题目链接：http://codeforces.com/contest/7/problem/D

D. Palindrome Degree

time limit per test

1 second

memory limit per test

256 megabytes

input

standard input

output

standard output

String s of length n is
called k-palindrome, if it is a palindrome itself, and its prefix and suffix of length  are (k - 1)-palindromes.
By definition, any string (even empty) is 0-palindrome.

Let's call the palindrome degree of string s such a maximum number k,
for which s is k-palindrome.
For example, "abaaba" has degree equals to 3.

You are given a string. Your task is to find the sum of the palindrome degrees of all its prefixes.

Input

The first line of the input data contains a non-empty string, consisting of Latin letters and digits. The length of the string does not exceed 5·106.
The string is case-sensitive.

Output

Output the only number — the sum of the polindrome degrees of all the string's prefixes.

Examples

input

a2A

output

1

input

abacaba

output

6

代码如下：

 #include<bits/stdc++.h>
 using namespace std;
 typedef long long LL;
 const double eps = 1e-;
 const int INF = 2e9;
 const LL LNF = 9e18;
 const int mod = 1e9+;
 const int maxn = 5e6+;

 char s[maxn];
 int dp[maxn];

 int main()
 {
     scanf("%s",s+);
     int l = , r = , m = ;
     for(int i = ; s[i]; i++)
     {
         l = l*+s[i];
         r = r+s[i]*m, m *= ;
         if(l==r)
             dp[i] = dp[i/]+;
     }

     int ans = ;
     for(int i = ; s[i]; i++)
         ans += dp[i];
     printf("%d\n",ans);
 }