HDU 2222 AC自动机 Keywords Search

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 131072/131072 K (Java/Others)
Total Submission(s): 65504 Accepted Submission(s): 21889

Problem Description

In the modern time, Search engine came into the life of everybody like Google, Baidu, etc.
Wiskey also wants to bring this feature to his image retrieval system.
Every image have a long description, when users type some keywords to find the image, the system will match the keywords with description of image and show the image which the most keywords be matched.
To simplify the problem, giving you a description of image, and some keywords, you should tell me how many keywords will be match.

Input

First line will contain one integer means how many cases will follow by.
Each case will contain two integers N means the number of keywords and N keywords follow. (N <= 10000)
Each keyword will only contains characters 'a'-'z', and the length will be not longer than 50.
The last line is the description, and the length will be not longer than 1000000.

Output

Print how many keywords are contained in the description.

Sample Input

1 5 she he say shr her yasherhs

Sample Output

Author

Wiskey

  1 #pragma comment(linker, "/STACK:1024000000,1024000000")
  2 #include<iostream>
  3 #include<cstdio>
  4 #include<cmath>
  5 #include<string>
  6 #include<queue>
  7 #include<algorithm>
  8 #include<stack>
  9 #include<cstring>
 10 #include<vector>
 11 #include<list>
 12 #include<set>
 13 #include<map>
 14 #include<bitset>
 15 #include<time.h>
 16 using namespace std;
 17 typedef struct trie_node{
 18     struct trie_node *fail;
 19     struct trie_node *next[27];
 20     int coun;
 21     trie_node(){
 22     fail=NULL;
 23     coun=0;
 24     memset(next,NULL,sizeof(next));
 25     }
 26 }trie;
 27 trie *q[500010];
 28 char keyword[55];
 29 char str[1000006];
 30 int head,tail;
 31 
 32 void insert(char *str,trie_node *root){
 33   trie_node *p=root;
 34   int i=0;
 35   int index;
 36   while(str[i]){
 37     index=str[i]-'a';
 38     if(p->next[index]==NULL) p->next[index]=new trie_node();
 39     p=p->next[index];
 40     ++i;
 41   }
 42   p->coun++;
 43 }
 44 
 45 
 46 void build_ac_automation(trie_node *root){
 47     int i;
 48     head=tail=0;
 49     root->fail=NULL;
 50     q[tail++]=root;
 51     while(head!=tail){
 52         trie_node *temp=q[head++];
 53         trie_node *p=NULL;
 54         for(i=0;i<26;i++){
 55             if(temp->next[i]!=NULL){
 56                 if(temp==root) temp->next[i]->fail=root;
 57                 else{
 58                     p=temp->fail;
 59                     while(p!=NULL){
 60                         if(p->next[i]!=NULL){
 61                         temp->next[i]->fail=p->next[i];
 62                         break;
 63                     }
 64                     p=p->fail;
 65                 }
 66                 if(p == NULL) temp->next[i]->fail=root;
 67             }
 68             q[tail++]=temp->next[i];
 69         }
 70     }
 71   }
 72 }
 73 
 74 
 75 int query(char *s,trie_node *root){
 76     int len=strlen(s);
 77     int cnt=0;
 78     trie_node *p=root;
 79     for(int i=0;i<len;i++){
 80         int index=s[i]-'a';
 81         while(p->next[index]==NULL&&p!=root) p=p->fail;
 82         p=p->next[index];
 83         p=(p==NULL)?root:p;
 84         trie_node *temp = p;
 85         while(temp!=root&&temp->coun!=-1){
 86             cnt+=temp->coun;
 87             temp->coun=-1;
 88             temp=temp->fail;
 89         }
 90     }
 91     return cnt;
 92 }
 93 
 94 int T,n;
 95 char s[1000006];
 96 int main(){
 97     scanf("%d",&T);
 98     for(int j=1;j<=T;j++){
 99         trie_node *root =new trie_node();
100         scanf("%d",&n);
101         for(int i=1;i<=n;i++){
102             scanf("%s",s);
103             insert(s,root);
104         }
105         build_ac_automation(root);
106         scanf("%s",str);
107         printf("%d
",query(str,root));
108     }
109 }

HDU 2222 AC自动机 Keywords Search

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