AC自动机 hdu2222

 1 #include <iostream>
 2 using namespace std;
 3 
 4 struct Node{
 5     Node *next[26];
 6     Node* fail;
 7     int count;
 8     Node(){
 9         for (int i = 0; i < 26; i++){
10             next[i] = NULL;
11         }
12         fail = NULL;
13         count = 0;
14     }
15 };
16 char words[51], s[1000001];
17 Node* d[500001];
18 void insert(char words[], Node *root){
19     int i, len = strlen(words), v;
20     Node *p = root;
21     for (i = 0; i < len; i++){
22         v = words[i] - ‘a‘;
23         if (p->next[v] == NULL){
24             p->next[v] = new Node();
25         }
26         p = p->next[v];
27     }
28     p->count++;
29 }
30 void build(Node *root){
31     int head, tail, i;
32     Node *p, *temp;
33     head = 0;
34     tail = 0;
35     root->fail = NULL;
36     d[head] = root;
37     while (head <= tail){
38         temp = d[head++];
39         for (i = 0; i < 26; i++){
40             if (temp->next[i] == NULL) continue;
41             if (temp == root){
42                 temp->next[i]->fail = root;
43             }
44             else{
45                 p = temp->fail;
46                 while (p != NULL){
47                     if (p->next[i] != NULL){
48                         temp->next[i]->fail = p->next[i];
49                         break;
50                     }
51                     p = p->fail;
52                 }
53                 if (p == NULL){
54                     temp->next[i]->fail = root;
55                 }
56             }
57             d[++tail] = temp->next[i];
58         }
59     }
60 }
61 
62 int query(char s[], Node* root){
63     int ans = 0, len = strlen(s), i, v;
64     Node *p = root, *temp;
65     for (i = 0; i < len; i++){
66         v = s[i] - ‘a‘;
67         while (p->next[v] == NULL && p != root){
68             p = p->fail;
69         }
70         p = (p->next[v] != NULL) ? p->next[v] : root;
71         temp = p;
72         while (temp != root&&temp->count != -1){
73             ans += temp->count;
74             temp->count = -1;
75             temp = temp->fail;
76         }
77     }
78     return ans;
79 }
80 
81 int main(){
82     int m, n, i;
83     Node *root;
84     cin >> m;
85     while (m--){
86         root = new Node();
87         cin >> n;
88         for (i = 0; i < n; i++){
89             cin >> words;
90             insert(words, root);
91         }
92         build(root);
93         cin >> s;
94         cout << query(s, root) << endl;
95     }
96 }