字典树模板

 typedef struct letter{
     int finished = 0;
     char le;
     letter *son, *ne;
     letter():le('\0'),son(NULL),ne(NULL){};
 }letter,*pointer;
  
 struct Trie
     {
         pointer rt;
         Trie() {rt = new letter();}
         void insert(char *word, int len)
             {
                 pointer u = rt;
                 for(int i = 0; i < len; i ++)
                     {
                         pointer v = u->son;
                         if(v != NULL)   while(v->ne != NULL && v->le != word[i]) v = v->ne;
                         if(v == NULL || v->ne == NULL && v->le != word[i])
                             {
                                 pointer &p = (v == NULL ? u->son :v->ne);
                                 p = new letter();
                                 p->le = word[i];
                                 if(i == len - 1)    ++ p->finished;
                                 u = p;
                             }
                         else u = v;
                     }
             }
          
         bool  find(char *word, int len)
             {
                 pointer u = rt;
                 for(int i = 0; i < len; i ++)
                     {
                         pointer v = u->son;
                         if(v == NULL)   return false;
                         while(v->ne != NULL && v->le != word[i])  v = v->ne;
                         if(v->ne == NULL && v->le != word[i]) return false;
                         u = v;
                     }
                 return true;
             }
     };