杭电 2222 Keywords Search

  1 #include<queue>
  2 #include<set>
  3 #include<cstdio>
  4 #include <iostream>
  5 #include<algorithm>
  6 #include<cstring>
  7 #include<cmath>
  8 using namespace std;
  9 char c[1000000+10];
 10 struct acnode{
 11     int sum;
 12     acnode* next[26];
 13     acnode* fail;
 14     acnode(){
 15         for(int i =0;i<26;i++)
 16             next[i]=NULL;
 17         fail= NULL;
 18         sum=0;
 19     }
 20 };
 21 acnode *root;
 22 int cnt;
 23 acnode* newnode(){
 24     acnode *p = new acnode;
 25     for(int i =0;i<26;i++)
 26         p->next[i]=NULL;
 27     p->fail = NULL;
 28     p->sum=0;
 29     return p;
 30 }
 31 //插入函数
 32 void Insert(char *s)
 33 {
 34     acnode *p = root;
 35     for(int i = 0; s[i]; i++)
 36     {
 37         int x = s[i] - ‘a‘;
 38         if(p->next[x]==NULL)
 39         {
 40             acnode *nn=newnode();
 41             for(int j=0;j<26;j++)
 42                 nn->next[j] = NULL;
 43             nn->sum = 0;
 44             nn->fail = NULL;
 45             p->next[x]=nn;
 46         }
 47         p = p->next[x];
 48     }
 49     p->sum++;
 50 }
 51 //获取fail指针，在插入结束之后使用
 52 void getfail(){
 53     queue<acnode*> q;
 54     for(int i = 0 ; i < 26 ; i ++ )
 55     {
 56         if(root->next[i]!=NULL){
 57             root->next[i]->fail = root;
 58             q.push(root->next[i]);
 59         }
 60     }
 61     while(!q.empty()){
 62         acnode* tem = q.front();
 63         q.pop();
 64         for(int i = 0;i<26;i++){
 65             if(tem->next[i]!=NULL)
 66             {
 67                 acnode *p;
 68                 if(tem == root){
 69                     tem->next[i]->fail = root;
 70                 }
 71                 else
 72                 {
 73                     p = tem->fail;
 74                     while(p!=NULL){
 75                         if(p->next[i]!=NULL){
 76                             tem->next[i]->fail = p->next[i];
 77                             break;
 78                         }
 79                         p=p->fail;
 80                     }
 81                     if(p==NULL)
 82                         tem->next[i]->fail = root;
 83                 }
 84                 q.push(tem->next[i]);
 85             }
 86         }
 87     }
 88 }
 89 //匹配函数
 90 void ac_automation(char *ch)
 91 {
 92     acnode *p = root;
 93     int len = strlen(ch);
 94     for(int i = 0; i < len; i++)
 95     {
 96         int x = ch[i] - ‘a‘;
 97         while(p->next[x]==NULL && p != root)//没匹配到，那么就找fail指针。
 98             p = p->fail;
 99         p = p->next[x];
100         if(!p)
101             p = root;
102         acnode *temp = p;
103         while(temp != root)
104         {
105            if(temp->sum >= 0)
106             /*
107             在这里已经匹配成功了，执行想执行的操作即可，怎么改看题目需求+
108             */
109            {
110                cnt += temp->sum;
111                temp->sum = -1;
112            }
113            else break;
114            temp = temp->fail;
115         }
116     }
117 }
118 
119 int main()
120 {   int t;
121     scanf("%d",&t);
122     while(t--){
123         cnt = 0;
124     int n;
125     cin>>n;
126 
127     root = newnode();
128     for(int i = 0 ;i < n;i++){
129         scanf("%s",c);
130         Insert(c);
131     }
132     getfail();
133     //int m ;
134     //cin>> m;
135     //for(int i = 0;i<m;i++){
136         scanf("%s",c);
137         ac_automation(c);
138     //}
139     cout<<cnt<<endl;
140     } 
141 
142     return 0;
143 }