poj 2001 trie

第一道trie

还需要写题来建立自己的代码习惯。

 1 #include <cstdio>
 2 #include <vector>
 3 #include <algorithm>
 4 #define maxn 20010
 5 using namespace std;
 6
 7 struct node {
 8     char v;
 9     int sz;
10     bool isword, mark;
11     node *son[26], *pre;
12 }pool[maxn], *tail=pool, *null=pool;
13
14 char temp[100];
15 struct Trie {
16     node *root;
17     vector<node*> stk;
18     node* newnode( node *p, char v ) {
19         node *nd = ++tail;
20         nd->sz = 0;
21         nd->v = v;
22         nd->isword = nd->mark = false;
23         nd->pre = p;
24         for( int i=0; i<26; i++ ) nd->son[i] = null;
25         return nd;
26     }
27     void insert( const char *str ) {
28         if( !root ) root=newnode(null,‘^‘);
29         node *nd=root;
30         while(1) {
31             if( *str ) {
32                 if( nd->son[*str-‘a‘]==null ) nd->son[*str-‘a‘]=newnode(nd,*str-‘a‘);
33                 nd->sz++;
34                 nd = nd->son[*str-‘a‘];
35                 str++;
36             } else {
37                 nd->isword = true;
38                 stk.push_back( nd );
39                 return;
40             }
41         }
42     }
43     void make_mark( node *nd ) {
44         if( nd->isword ) {
45             nd->mark = true;
46             for( int i=0; i<26; i++ )
47                 if( nd->son[i]!=null ) make_mark(nd->son[i]);
48         } else if( nd->sz==1 ) {
49             nd->mark = true;
50         } else {
51             for( int i=0; i<26; i++ )
52                 if( nd->son[i]!=null ) make_mark(nd->son[i]);
53         }
54     }
55     char *get( node *bt ) {
56         while( !bt->mark ) bt=bt->pre;
57         int i;
58         for( i=0; bt!=root; i++,bt=bt->pre )
59             temp[i] = bt->v+‘a‘;
60         temp[i] = 0;
61         reverse( temp, temp+i );
62         return temp;
63     }
64     void print( node *nd ) {
65         fprintf( stderr, "nd %d ch %c mark %d\n", nd-pool, nd->v+‘a‘, nd->mark );
66         for( int i=0; i<26; i++ )
67             if( nd->son[i]!=null ) print(nd->son[i]);
68     }
69 }T;
70
71 void pt( char *st ) {
72     fprintf( stderr, "%s\n", st );
73 }
74 char str[1010][30];
75 int main() {
76     int i;
77     for( i=0; ; i++ ) {
78         if( scanf( "%s", str[i] )!=1 ) {
79             i--;
80             break;
81         }
82         T.insert( str[i] );
83     }
84     for( int i=0; i<26; i++ )
85         if( T.root->son[i]!=null )
86             T.make_mark( T.root->son[i] );
87     for( int t=0; t<=i; t++ )
88         printf( "%s %s\n", str[t], T.get(T.stk[t]) );
89 }