HDU 1251 统计难题

  
    

   
     /*
   
     
用指针写的最基本的字典树
最基本的字典树
  
    
  
    

   
     释放内存也没写，第一题字典树 

   
     */
   
     

#include 
   
     <
   
     stdio.h
   
     >
   
     
#include 
   
     <
   
     stdlib.h
   
     >
   
     
#include 
   
     <
   
     string
   
     .h
   
     >
   
     

   
     const
   
      
   
     int
   
      MAXN 
   
     =
   
      
   
     100000
   
     ;

   
     struct
   
      Trie
{
 
   
     int
   
      n; 
   
     //
   
     记录走过这条路径的单词数量
   
     

   
      
   
     struct
   
      Trie 
   
     *
   
     next[
   
     26
   
     ];
};
Trie 
   
     *
   
     root;

   
     void
   
      init(Trie 
   
     *
   
     t){ 
   
     //
   
     初始化函数 所有孩子节点置为空
   
     

   
      
   
     for
   
     (
   
     int
   
      i 
   
     =
   
      
   
     0
   
     ; i 
   
     <
   
      
   
     26
   
     ; i
   
     ++
   
     ){
 t 
   
     ->
   
      next[i] 
   
     =
   
      NULL;
 }
 t 
   
     ->
   
      n 
   
     =
   
      
   
     0
   
     ;
}

   
     void
   
      insert(
   
     char
   
      
   
     *
   
     str){
 Trie 
   
     *
   
     t 
   
     =
   
      root;
 
   
     while
   
     (
   
     *
   
     str){
 
   
     int
   
      i 
   
     =
   
      
   
     *
   
     str 
   
     -
   
      
   
     '
   
     a
   
     '
   
     ;
 
   
     if
   
     (t 
   
     ->
   
      next[i] 
   
     ==
   
      NULL){
 t 
   
     ->
   
      next[i] 
   
     =
   
      (Trie
   
     *
   
     )malloc(
   
     sizeof
   
     (Trie));
 init(t 
   
     ->
   
      next[i]);
 t 
   
     ->
   
      next[i] 
   
     ->
   
      n
   
     ++
   
     ; 
 } 
   
     else
   
      {
 t 
   
     ->
   
      next[i] 
   
     ->
   
      n
   
     ++
   
     ;
 }
 t 
   
     =
   
      t 
   
     ->
   
      next[i];
 str
   
     ++
   
     ;
 }
}

   
     int
   
      find(
   
     char
   
      
   
     *
   
     s){
 Trie 
   
     *
   
     t 
   
     =
   
      root;
 
   
     while
   
     (
   
     *
   
     s){
 
   
     int
   
      i 
   
     =
   
      
   
     *
   
     s 
   
     -
   
      
   
     '
   
     a
   
     '
   
     ;
 
   
     if
   
     (t 
   
     ->
   
      next[i] 
   
     ==
   
      NULL)
 
   
     return
   
      
   
     0
   
     ;
 t 
   
     =
   
      t 
   
     ->
   
      next[i];
 s
   
     ++
   
     ;
 }
 
   
     return
   
      t 
   
     ->
   
      n;
}

   
     int
   
      main(){
 root 
   
     =
   
      (Trie
   
     *
   
     )malloc(
   
     sizeof
   
     (Trie));
 
   
     for
   
     (
   
     int
   
      i 
   
     =
   
      
   
     0
   
     ; i 
   
     <
   
      
   
     26
   
     ; i
   
     ++
   
     )
 root 
   
     ->
   
      next[i] 
   
     =
   
      NULL;
 root 
   
     ->
   
      n 
   
     =
   
      
   
     0
   
     ;
 
   
     char
   
      str[
   
     11
   
     ];
 
   
     while
   
     (gets(str),strcmp(str,
   
     ""
   
     ) 
   
     !=
   
      
   
     0
   
     ){
 insert(str);
 }
 
   
     while
   
     (gets(str)){
 printf(
   
     "
   
     %d\n
   
     "
   
     ,find(str));
 }
 
   
     return
   
      
   
     0
   
     ;
}