KMP + 求最小循环节 --- HUST 1010 - The Minimum LengthThe Minimum Length Problem's Link: http://acm.hust.edu.cn/problem/show/1010

Mean: 

给你一个字符串，求这个字符串的最小循环节。

analyse:

KMP之next数组的运用。裸的求最小循环节。

Time complexity: O(N)

Source code: 

/*

* this code is made by crazyacking

* Verdict: Accepted

* Submission Date: 2015-07-28-07.12

* 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;

int n;

char s[MAXN];

int Next[MAXN];

void getNext()

{

     Next[0]=0;f

     for(int i=1,k=0;i<n;++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))

           n=strlen(s);

           getNext();

           int min_cycle=n-Next[n-1];

           printf("%d\n",min_cycle);

     return 0;