Description
Problem D: Power Strings
Given two strings a and b we define a*b to be their concatenation. For example, ifa = "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).
Each test case is a line of input representing s, a string of printable characters. For eachs you should print the largest n such that s = a^n for some stringa. 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.
Sample Input
abcd
aaaa
ababab
.
Output for Sample Input
1
4
3
题意:求循环节
思路:KMP模板求循环节
#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
using namespace std;
const int MAXN = 1000000;
char str[MAXN];
int next[MAXN];
int main() {
while (scanf("%s", str) != EOF && str[0] != '.') {
int len = strlen(str);
int i = 0, j = -1;
next[0] = -1;
while (i < len) {
if (j == -1 || str[i] == str[j]) {
i++, j++;
next[i] = j;
}
else j = next[j];
}
printf("%d\n", len/(len-next[len]));
}
return 0;
}