E - Period poj1611（kmp 计算前缀循环节）

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t=i-next[i];表示已i结尾的前缀的循环节，关于kmp的next数组的性质，我前面的文章有介绍

#include<cstdio>
#include<algorithm>
#include<cmath>
#include<string>
#include<cstring>
//#include<bits/stdc++.h>
using namespace std;
template<class T>inline T read(T&x)
{
    char c;
    while((c=getchar())<=32)if(c==EOF)return 0;
    bool ok=false;
    if(c=='-')ok=true,c=getchar();
    for(x=0; c>32; c=getchar())
        x=x*10+c-'0';
    if(ok)x=-x;
    return 1;
}
template<class T> inline T read_(T&x,T&y)
{
    return read(x)&&read(y);
}
template<class T> inline T read__(T&x,T&y,T&z)
{
    return read(x)&&read(y)&&read(z);
}
template<class T> inline void write(T x)
{
    if(x<0)putchar('-'),x=-x;
    if(x<10)putchar(x+'0');
    else write(x/10),putchar(x%10+'0');
}
template<class T>inline void writeln(T x)
{
    write(x);
    putchar('\n');
}
//-------ZCC IO template------
const int maxn=1000001;
const double inf=999999999;
#define lson (rt<<1),L,M
#define rson (rt<<1|1),M+1,R
#define M ((L+R)>>1)
#define For(i,t,n) for(int i=(t);i<(n);i++)
typedef long long  LL;
typedef double DB;
typedef pair<int,int> P;
#define bug printf("---\n");
#define mod  1000000007
int nex[maxn];
char a[maxn];

void getnext(char*s)
{
    int i=0,j=-1;
    nex[0]=-1;
    int len=strlen(s);
    while(i<len)
    {
        if(j==-1||s[i]==s[j])
            nex[++i]=++j;
        else
            j=nex[j];
    }
}
int main()
{
    //#ifndef ONLINE_JUDGE
    //freopen("in.txt","r",stdin);
    //freopen("zccccc.txt","w",stdout);
    //#endif // ONLINE_JUDGE
    int n,m,i,j,t,k;
    int T;
    int cas=1;
    while(read(n)&&n)
    {
        printf("Test case #%d\n",cas++);
        scanf("%s",a);
        int len=strlen(a);
        getnext(a);
        for(i=0;i<=len;i++)
        {
            t=i-nex[i];
            if(i%t==0&&i/t>1)
            {
                printf("%d %d\n",i,i/t);
            }
        }
        printf("\n");
    }

    return 0;
}

E - Period poj1611（kmp 计算前缀循环节）

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原文地址：http://blog.csdn.net/u013167299/article/details/45080675