hdu--1251--字典树

 1 #include <iostream>
 2 #include <cstring>
 3 using namespace std;
 4 
 5 const int size = 26;
 6 char str[size];
 7 typedef struct trie
 8 {
 9     trie* next[size];
10     int cnt;
11 };
12 trie* root;
13 
14 void init()
15 {
16     root = new trie;
17     for( int i = 0 ; i<size ; i++ )
18         root->next[i] = NULL;
19 }
20 
21 void create( char* str )
22 {
23     int len = strlen(str);
24     trie* p = root;
25     //trie* q;
26     for( int i = 0 ; i<len ; i++ )
27     {
28         int id = str[i] - ‘a‘;
29         if( p->next[id] == NULL )
30         {
31             //q = new trie;
32             p->next[id] = new trie;
33             p->next[id]->cnt = 1;
34             for( int j = 0 ; j<size ; j++ )
35             {
36                 p->next[id]->next[j] = NULL;
37             }
38             //p->next[id] = q;
39         }
40         else
41         {
42             p->next[id]->cnt ++;
43         }
44         p = p->next[id];
45     }
46 }
47 
48 int find( char* str )
49 {
50     int len = strlen(str);
51     trie* p = root;
52     for( int i = 0 ; i<len ; i++ )
53     {
54         int id = str[i] - ‘a‘;
55         p = p->next[id];
56         if( p==NULL )
57         {
58             return 0;
59         }
60     }
61     return p->cnt;
62 }
63 
64 int main()
65 {
66     init();
67     while( gets(str) && str[0]!=‘\0‘ )
68     {
69         create( str );
70     }
71     while( cin >> str )
72     {
73         cout << find(str) << endl;
74     }
75     return 0;
76 }