hdu----(2222)Keywords Search(trie树)
Keywords Search
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 35683 Accepted Submission(s): 11520
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
3
Author
Wiskey
代码：
字典树
1 /*hdu 2222 字典树*/
2 //#define LOCAL
3 #include<cstdio>
4 #include<cstring>
5 #include<iostream>
6 using namespace std;
7 struct Trie
8 {
9 struct Trie *next[26];
10 int tail;
11 };
12 char str[55];
13 char ss[1000005];
14 void in_Trie(char *s,Trie *root)
15 {
16 Trie *cur=root,*newcur;
17 for(int i=0;s[i]!='\0';i++)
18 {
19 if(cur->next[s[i]-'a']==NULL)
20 {
21 newcur=new Trie; //(Trie*)malloc(sizeof(sizeof(Trie)));
22 for(int j=0;j<26;j++)
23 newcur->next[j]=NULL;
24 newcur->tail=0;
25 cur->next[s[i]-'a']=newcur;
26 }
27 cur=cur->next[s[i]-'a'];
28 }
29 cur->tail++;
30 }
31 int query(char *s,Trie *root)
32 {
33 int i=0,cnt=0;
34 Trie *cur;
35 for(int j=0;s[j]!='\0';j++)
36 {
37 cur=root;
38 for(i=j;s[i]!='\0';i++){
39 if(cur->next[s[i]-'a']!=NULL){
40 cur=cur->next[s[i]-'a'];
41 cnt+=cur->tail;
42 cur->tail=0; //只需求出第一次出现的
43 }
44 else break;
45 }
46 }
47 return cnt;
48 }
49 void dele(Trie *root)
50 {
51 for(int i=0 ; i<26 ; i++ )
52 if(root->next[i]!=NULL)
53 dele(root->next[i]);
54 // free(root);
55 delete root;
56 }
57 int main()
58 {
59 #ifdef LOCAL
60 freopen("test.in","r",stdin);
61 #endif
62 int t,i,n;
63 Trie *root;
64 scanf("%d",&t);
65 while(t--)
66 {
67 root = new Trie ;
68 for(int j=0;j<26;j++)
69 root->next[j]=NULL;
70 root->tail=0;
71 scanf("%d",&n);
72 for(i=0;i<n;i++){
73 scanf("%s",str);
74 in_Trie(str,root);
75 }
76 scanf("%s",ss);
77 printf("%d\n",query(ss,root));
78 dele(root);
79 }
80 return 0;
81 }