Keywords Search （AC自动机模版题）

 1 #include <stdio.h>
 2 #include <iostream>
 3 #include <algorithm>
 4 #include <string.h>
 5 #include <stdlib.h>
 6 #include <math.h>
 7 #include <queue>
 8 #include <set>
 9 
10 #define INF 0x3f3f3f3f
11 #define pii pair<int,int>
12 using namespace std;
13 const int maxn = 1e6+10;
14 
15 char buf[maxn];
16 struct ac_automation{
17     int next[maxn][26],fail[maxn],end[maxn];
18     int root,L;
19     int newnode(){
20         for (int i=0;i<26;i++)
21         {
22             next[L][i] = -1;
23         }
24         end[L++] = 0;
25         return L-1;
26     }
27     void init(){
28         L = 0;
29         root = newnode();
30     }
31     void insert(char buf[]){
32         int len = strlen(buf);
33         int now = root;
34         for (int i=0;i<len;i++){
35             if (next[now][buf[i]-‘a‘] == -1)
36                 next[now][buf[i]-‘a‘] = newnode();
37             now = next[now][buf[i]-‘a‘];
38         }
39         end[now]++;
40     }
41     void build(){
42         queue<int > Q;
43         fail[root] = root;
44         for (int i=0;i<26;i++)
45         {
46             if (next[root][i] == -1)
47                 next[root][i] = root;
48             else{
49                 fail[next[root][i]] = root;
50                 Q.push(next[root][i]);
51             }
52         }
53         while (!Q.empty()){
54             int now = Q.front();
55             Q.pop();
56             for (int i=0;i<26;i++){
57                 if (next[now][i] == -1)
58                     next[now][i] = next[fail[now]][i];
59                 else{
60                     fail[next[now][i]] = next[fail[now]][i];
61                     Q.push(next[now][i]);
62                 }
63             }
64         }
65     }
66     int querry(char buf[]){
67         int len = strlen(buf);
68         int now = root;
69         int res = 0;
70         for (int i=0;i<len;i++){
71             now = next[now][buf[i]-‘a‘];
72             int temp = now;
73             while (temp!=root){
74                 res += end[temp];
75                 end[temp] = 0;
76                 temp = fail[temp];
77             }
78         }
79         return res;
80     }
81 }ac;
82 
83 int main(){
84     int T;
85     scanf("%d",&T);
86     while (T--){
87         int n;
88         scanf("%d",&n);
89         ac.init();
90         for (int i=0;i<n;i++){
91             scanf("%s",buf);
92             ac.insert(buf);
93         }
94         ac.build();
95         scanf("%s",buf);
96         printf("%d\n",ac.querry(buf));
97     }
98     return 0;
99 }