HDU 1358 Period

 1 #include<iostream> 
 2 #include<cstring>
 3 #include<string>
 4 using namespace std;
 5 
 6 const int maxn = 1000000+5;
 7 
 8 int next[maxn], n;
 9 char pattern[maxn];
10 
11 void get_next()
12 {
13     int i, j;
14     i = -1;
15     j = 0;
16     ::next[0] = -1;
17     while (j<n)
18     {
19         if (i == -1 || pattern[i] == pattern[j])
20         {
21             ::next[++j] = ++i;
22         }
23         else
24             i = ::next[i];
25     }
26 }
27 
28 void solve()
29 {
30     for (int i = 2; pattern[i-1]; i++)
31     {
32         int t = i - ::next[i];
33         if (i%t == 0 && i/t>1)
34         {
35             cout << i  << " " << i/t << endl;
36         }
37     }
38 }
39 
40 int main()
41 {
42     //freopen("D:\\txt.txt", "r", stdin);
43     int kase = 0;
44     while (cin>>n && n)
45     {
46         scanf("%s", pattern);
47         //cout << pattern << endl << text << endl;
48         get_next();
49         cout << "Test case #" << ++kase << endl;
50         solve();
51         cout << endl;
52     }
53     return 0;
54 }