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 = 10;

char t[12];
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 = 0; i < len; i++ )
    {
        int tmp = t[i]-'0';
        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 = 0; i < maxn; i++ )
        if( root->next[i] != NULL ) 
            flag = false;
}

void del( node* root )
{
    if( root == NULL ) return;
    for( int i = 0; 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 = 1; i <= n; i++ )
        {
            scanf( "%s", t );
            if(flag)
                create(r);
        }

        del(r);

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

    }
    return 0;
}