Time Limit: 3000MS | Memory Limit: 65536K | |
Total Submissions: 56162 | Accepted: 23370 |
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
abcdaaaaababab.
Sample Output
143
Hint
This problem has huge input, use scanf instead of cin to avoid time limit exceed.
Source
kmp的经典应用
设$len$表示字符串的长度,$next[i]$表示$i$号字符串的最长公共前后缀的长度
如果$len \ mod \ next[len] == 0$,那么循环节的长度为$n / next[len]$
#include#include using namespace std;const int MAXN = 1e6 + 10;char s[MAXN];int fail[MAXN];int main() {#ifdef WIN32 freopen("a.in", "r", stdin); //freopen("a.out", "w", stdout);#endif while(scanf("%s", s + 1) && s[1] != '.') { int N = strlen(s + 1), now = 0; for(int i = 2; i <= N; i++) { while(now && s[i] != s[now + 1]) now = fail[now]; if(s[i] == s[now + 1]) now++; fail[i] = now; } if(N % (N - fail[N]) == 0) printf("%d\n", N / (N - fail[N])); else printf("1\n"); } return 0;}