Phone List HDU1671 字典树Trie

模板题...不过会爆内存,要小心

 #include <iostream>
 #include <cstdio>
 #include <string.h>
 #pragma warning ( disable : 4996 )
 using namespace std;

 const int inf = 0x3f3f3f3f;
 const int maxn = ;

 char t[];
 bool flag;

 struct node {
     bool end;
     node* next[maxn];
     node()
     {
         end = false;
         memset( next, NULL, sizeof(next) );
     }
 }*r;

 void create( node* root )
 {
     int len = strlen(t);

     for ( int i = ; i < len; i++ )
     {
         int tmp = t[i]-'';
         if ( root->next[tmp] == NULL )
         {
             node* next = new node;

             root->next[tmp] = next;
         }

         root = root->next[tmp];
         if(root->end) flag = false;
     }
     root->end = true;
     for( int i = ; i < maxn; i++ )
         if( root->next[i] != NULL )
             flag = false;
 }

 void del( node* root )
 {
     if( root == NULL ) return;
     for( int i = ; i < maxn; i++ )
         del(root->next[i]);
     free(root);
 }

 int main()
 {
     int all;
     cin >> all;
     while (all--)
     {
         flag = true;
         int n;
         cin >> n;

         r = new node();

         for ( int i = ; i <= n; i++ )
         {
             scanf( "%s", t );
             if(flag)
                 create(r);
         }

         del(r);

         if(flag)
             cout << "YES" << endl;
         else
             cout << "NO" << endl;

     }
     return ;
 }