KMP + 求最小循环节 --- POJ 2406 Power Strings

Problem's Link: http://poj.org/problem?id=2406

[b]Mean:[/b]

给你一个字符串，让你求这个字符串最多能够被表示成最小循环节重复多少次得到。

[b]analyse:[/b]

KMP之next数组的运用。裸的求最小循环节。

[b]Time complexity: O(N)[/b]

[b]Source code: [/b]

/*
* this code is made by crazyacking
* Verdict: Accepted
* Submission Date: 2015-07-28-08.23
* Time: 0MS
* Memory: 137KB
*/
#include <queue>
#include <cstdio>
#include <set>
#include <string>
#include <stack>
#include <cmath>
#include <climits>
#include <map>
#include <cstdlib>
#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>
#define LL long long
#define ULL unsigned long long
using namespace std;
const int MAXN=1000010;
char s[MAXN];
int Next[MAXN];
void getNext(int len)
{
Next[0]=0;
for(int i=1,k=0;i<len;++i)
{
while(s[i]!=s[k] && k) k=Next[k-1];
if(s[i]==s[k]) ++k;
Next[i]=k;
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
while(~scanf("%s",s) && s[0]!='.')
{
int len=strlen(s);
getNext(len);
int min_cycle=len-Next[len-1];
if(len%min_cycle!=0) printf("1\n");
else printf("%d\n",len/min_cycle);
}
return 0;
}
/*

*/