MiYu原创, 转帖请注明 : 转载自 ______________白白の屋
题目地址:
http://acm.hdu.edu.cn/showproblem.php?pid=1671
题目描述:
Phone List
Time Limit: 3000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 1733 Accepted Submission(s): 572
1. Emergency 911
2. Alice 97 625 999
3. Bob 91 12 54 26
In this case, it’s not possible to call Bob, because the central would direct your call to the emergency line as soon as you had dialled the first three digits of Bob’s phone number. So this list would not be consistent.
2 3 911 97625999 91125426 5 113 12340 123440 12345 98346
NO YES
这个题有很多种方法, 大牛用静态字典树....哥不会,只会动态的, 结果 MLE 了20几次... , 很纠结的是,我的结构体用的是局部变量, 到现在还是
没明白为什么他不会自动释放...最后加了动态数组的释放才A掉............... 然后尝试了一下 STL ...比动态字典还快......
动态字典代码:
/*
MiYu原创, 转帖请注明 : 转载自 ______________白白の屋
http://www.cnblog.com/MiYu
Author By : MiYu
Test : 1
Program : 1671
*/
#include <iostream>
using namespace std;
typedef struct dict DIC;
int f = 0;
DIC *root = NULL;
struct dict {
dict (){ n = 0; flag = false;memset ( child , 0 , sizeof ( child ) ); }
~dict () { del ( root ); }
static void insert ( char *ins )
{
DIC *cur = root,*now;
int len = strlen ( ins );
if ( len == 0 ) return ;
for ( int i = 0; i != len; ++ i )
{
if ( cur->flag || ( i == len - 1 && cur->child[ ins[i] - '0' ] != NULL ) )
f = 1;
if ( cur->child[ ins[i] - '0' ] != NULL )
{
cur = cur->child[ ins[i] - '0' ];
cur->n ++;
}
else
{
now = new DIC;
cur->child[ ins[i] - '0' ] = now;
now->n ++;
cur = now;
}
}
cur->flag = true;
}
void del ( DIC * node )
{
if ( node == NULL )
return;
for ( int i = 0; i != 10; ++ i )
{
if ( node->child[i] != NULL )
del ( node->child[i] );
}
free ( node );
}
private:
DIC *child[10];
int n;
bool flag;
};
char num[11];
int main ()
{
int T,N;
scanf ( "%d",&T );
while ( T -- )
{
DIC dict;
root = &dict;
f = 0;
scanf ( "%d",&N );
for ( int i = 0; i != N; ++ i )
{
scanf ( "%s",num );
if ( f == 0 ) dict.insert ( num );
}
puts ( f ? "NO" : "YES" );
}
return 0;
}
STL 代码 :
/*
MiYu原创, 转帖请注明 : 转载自 ______________白白の屋
http://www.cnblog.com/MiYu
Author By : MiYu
Test :
Program :
*/
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;
char num[11];
bool cmp ( const string &a, const string &b )
{
return strcmp ( a.c_str(), b.c_str() ) < 0;
}
int main ()
{
int T,N;
scanf ( "%d",&T );
while ( T -- )
{
int f = 0;
scanf ( "%d",&N );
vector < string > vec;
for ( int i = 0; i != N; ++ i )
{
scanf ( "%s",num );
vec.push_back ( string ( num ) );
}
sort ( vec.begin(), vec.end(),cmp1 );
for ( int i = 1; i < N; ++ i )
{
if ( vec[i].find ( vec[i-1] ) == 0 )
{
f = 1;
break;
}
}
puts ( f ? "NO" : "YES" );
}
return 0;
}
AMB 大牛的 静态代码 :