【AC自动机】Keywords Search

 1 #pragma GCC optimize(2)
 2 
 3 #include<queue>
 4 #include<cstdio>
 5 #include<cstring>
 6 #include<iostream>
 7 #include<algorithm>
 8 using namespace std;
 9 const int N = 5e5+1e4;
10 const int M = 1e6+10;
11 queue < int > Q ;
12 typedef struct Aho_Corasick_Automaton{
13     int Son[N][26],End[N],Fail[N],idx;
14     void Init(){
15         idx = 0 ;
16         while( !Q.empty() ) Q.pop() ;
17         memset(Son , 0 , sizeof Son );
18         memset(End , 0 , sizeof End );
19         memset(Fail, 0 , sizeof Fail );
20     }
21     void Insert(char s[]){
22         int p = 0 ;
23         for(int i=0;s[i];i++){
24             int t = s[i] - ‘a‘;
25             if( !Son[p][t] )
26                 Son[p][t] = ++idx;
27             p = Son[p][t] ;
28         }
29         End[p] ++ ;
30     }
31 
32     void Build(){
33         for(int i=0;i<26;i++){
34             if( Son[0][i] )
35                 Fail[Son[0][i]] = 0 ,Q.push(Son[0][i]);
36         }
37 
38         while( !Q.empty() ){
39             int u = Q.front() ;
40             Q.pop();
41 
42             for(int i=0;i<26;i++){
43                 if( Son[u][i] ){
44                     Fail[Son[u][i]] = Son[Fail[u]][i] ;
45                     Q.push( Son[u][i] );
46                 }else{
47                     Son[u][i] = Son[Fail[u]][i];
48                 }
49             }
50         }
51     }
52 
53     void Query(char s[]){
54         int p = 0,res = 0;
55         for(int i=0;s[i];i++){
56             int t = s[i] - ‘a‘;
57             p = Son[p][t] ;
58             for(int j=p ; j && ~End[j] ; j = Fail[j] ){
59                 res += End[j] ;
60                 End[j] = -1 ;
61             }
62         }
63         //printf("%d\n",res);
64         cout << res << endl ;
65     }
66 }AC_Machine ;
67 AC_Machine AC ;
68 char s[M];
69 int n;
70 int main(){
71 
72     ios_base :: sync_with_stdio(false);
73     cin.tie(NULL) , cout.tie(NULL);
74     int T;
75     cin >> T ;
76     while(T--){
77         cin >> n ;
78         AC.Init();
79         for(int i=0;i<n;i++){
80             //scanf("%s",s);
81             cin >> s ;
82             AC.Insert(s);
83         }
84         AC.Build();
85         //scanf("%s",s);
86         cin >> s ;
87         AC.Query(s);
88     }
89     return 0;
90 }