Problem Description
Given two strings a and b we define a*b to be their concatenation. For example, if a = "abc" and b = "def" then a*b = "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
.
Sample Output
1
4
3
Hint
This problem has huge input, use scanf instead of cin to avoid time limit exceed.
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#define N 1000005
int main()
{
int num[N];
char s[N];
int n,i;
while(scanf("%s",s),s[0]!='.')// 逗号表达式代替 if break
{
int j = -1;//j 表示前缀,i 表示后缀
num[0] = -1;
n = strlen(s);
for(i=0;i<n;)
{
if(j == -1||s[i] == s[j])num[++i] = ++j;
else j = num[j];
}
if(n%(n-num[n])==0) //解决特例 aabaabaa abcabcabc(符合条件)
printf("%d\n",n/(n-num[n]));
else puts("1");
}
return 0;
}