[HDU 1358]Period[kmp求周期]

#include <cstring>
#include <cstdio>
const int MAXN = 1000005;
int next[MAXN];
char s[MAXN];
//93MS	5092K
void prekmp()
{
next[0] = -1;
int j = -1;
for(int i=1;s[i];i++)
{
while(j!=-1 && s[j+1]!=s[i])    j = next[j];
if(s[j+1]==s[i])    j++;
next[i] = j;
}
}

int main()
{
int n,cas = 0;
while(scanf("%d",&n) && n)
{
scanf("%s",s);
printf("Test case #%d\n",++cas);
prekmp();
int len;
for(int i=1;i<n;i++)
{
len = i-next[i];
int k;
if(!((i+1)%len))
{
if((k=(i+1)/len)>1)
printf("%d %d\n",i+1,k);
}
}
printf("\n");
}

}