Power Strings

Description
Given two strings a and b we define ab to be their concatenation. For example, if a = “abc” and b = “def” then ab = “abcdef”. If we think of concatenation as multiplication, exponentiation by a non-negative integer is defined in the normal way: a^0 = “” (the empty string) and a^(n+1) = a*(a^n).
Input
Each test case is a line of input representing s, a string of printable characters. The length of s will be at least 1 and will not exceed 1 million characters. A line containing a period follows the last test case.

Output
For each s you should print the largest n such that s = a^n for some string a.

Sample
Input

abcd

aaaa

ababab

.

Output

1

4

3

Hint
This problem has huge input, use scanf instead of cin to avoid time limit exceed.

#include<bits/stdc++.h>

using namespace std;

char s[1000010];
int Next[1000010];
int len;

void get_next()
{
    int i = 0;
    int j = -1;
    Next[0] = -1;
    while(i < len)
    {
        if(j == -1 || s[i] == s[j])
        {
            Next[++i] = ++j;
        }
        else j = Next[j];
    }
}
int main()
{
    while(scanf("%s", s) && s[0] != '.')
    {
        len = strlen(s);
        get_next();
        if(len % (len - Next[len]) == 0)
            printf("%d\n", len / (len - Next[len]));
        else
            printf("1\n");
    }
    return 0;
}