POJ1961 KMP算法

 1 //Memory: 5700K        Time: 641MS
 2 #include <iostream>
 3 #include <cstring>
 4 #include <string>
 5 
 6 using namespace std;
 7 
 8 const int maxn = 1000010;
 9 
10 int prefix[maxn];
11 string s;
12 
13 void init()
14 {
15     int l = s.size();
16     memset(prefix, 0, sizeof(prefix));
17     int k = 0;
18     for (int i = 2; i <= l; i++) {
19         while (k > 0 && s[k] != s[i - 1])
20             k = prefix[k];
21         if (s[k] == s[i - 1])
22             k++;
23         prefix[i] = k;
24     }
25 }
26 
27 int main()
28 {
29     int n;
30     int case_num = 1;
31     while (cin >> n && n) {
32         cin >> s;
33         init();
34         int l = s.size();
35         cout << "Test case #" << case_num++ << endl;
36         for (int k = 1; k <= l; k++) {
37             if ( prefix[k] != 0 && k % (k - prefix[k]) == 0) {
38                 cout << k << " " << k / (k - prefix[k]) << endl;
39             }
40         }
41         cout << endl;
42     }
43     return 0;
44 }