uva 1328 - Period

#include<cstdio>
#include<cstring>
#define maxn 1000009
using namespace std;

char s[maxn];
int next[maxn],n;

void getnext()
{
int j=-1,i=0;
next[0]=-1;
while(i<n)
{
if(j==-1||s[i]==s[j])
{
j++,i++;
next[i]=j;
}
else j=next[j];
}
}

int main()
{
int ca=1;
while(scanf("%d",&n)&&n)
{
memset(next,0,sizeof next);
scanf("%s",s);
getnext();
printf("Test case #%d\n",ca++);
for(int i=2;i<=n;i++)
if(next[i]>0&&i%(i-next[i])==0)
printf("%d %d\n",i,i/(i-next[i]));
puts("");
}
return 0;
}