poj2752 Seek the Name, Seek the Fame

http://poj.org/problem?id=2752

水题一枚：next函数应用

#include<stdio.h>
#include<string.h>
char str1[500005];
int next[500005];
int a[500005];
void get_next(int x)
{
    int i=0,j=-1;
    next[0]=-1;
    while(i<x)
    {
        if(j==-1||str1[i]==str1[j])
        {
            i++;
            j++;
            //if(str1[i]!=str1[j])
            next[i]=j;
            //else next[i]=next[j];
        }
        else j=next[j];
    }
}

int main()
{
    while(~scanf("%s",str1))
    {
        int len;
        int len1=strlen(str1);
        get_next(len1);
        int k=0;
        while(len1>0)
        {
            a[k++]=len1;
            len1=next[len1];
        }
        for(int i=k-1;i>0;i--)
        printf("%d ",a[i]);
        printf("%d\n",a[0]);
    }
}