POJ 2406 Power Strings KMP 最小循環節

題意：給出一個字符串，求出字符串中重複次數最多的子串的重複次數
思路：在複習一遍，n-fail[n]表示長度爲n的字符串中最小循環節的長度，首先求出fail數組，再求出串中最小循環節長度，若長度可被總長整除，則答案即爲總長/循環節長度，否則就是1

#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<vector>
#include<stack> 
#include<queue>
#include<map>
#include<algorithm>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int maxn = 1e6+10;
const int mod = 1e9+7;
const int inf = 0x3f3f3f3f;
int n, m, fail[maxn];
char s[maxn];
void getFail()
{
	fail[0] = -1;
	int k = -1, j = 0;
	while (j < n) {
		if (k == -1 || s[j] == s[k]) {
			j++;
			k++;
			fail[j] = k;
		}
		else
			k = fail[k];
	}
}
int main()
{
	while (~scanf("%s", s) && !(strlen(s) == 1 && s[0] == '.')) {
		n = strlen(s);
		getFail();
		int k = n-fail[n];
		printf("%d\n", n%k == 0 ? n/k : 1);
	}
	return 0;
}