POJ 2251 题解

Dungeon Master

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 27520		Accepted: 10776

Description

You are trapped in a 3D dungeon and need to find the quickest way out! The dungeon is composed of unit cubes which may or may not be filled with rock. It takes one minute to move one unit north, south, east, west, up or down. You cannot move diagonally and the maze is surrounded by solid rock on all sides.

Is an escape possible? If yes, how long will it take?

Input

The input consists of a number of dungeons. Each dungeon description starts with a line containing three integers L, R and C (all limited to 30 in size). 
L is the number of levels making up the dungeon. 
R and C are the number of rows and columns making up the plan of each level. 
Then there will follow L blocks of R lines each containing C characters. Each character describes one cell of the dungeon. A cell full of rock is indicated by a '#' and empty cells are represented by a '.'. Your starting position is indicated by 'S' and the exit by the letter 'E'. There's a single blank line after each level. Input is terminated by three zeroes for L, R and C.

Output

Each maze generates one line of output. If it is possible to reach the exit, print a line of the form

Escaped in x minute(s).

where x is replaced by the shortest time it takes to escape. 
If it is not possible to escape, print the line

Trapped!

Sample Input

3 4 5
S....
.###.
.##..
###.#

#####
#####
##.##
##...

#####
#####
#.###
####E

1 3 3
S##
#E#
###

0 0 0

Sample Output

Escaped in 11 minute(s).
Trapped!

————————————分割线————————————

 

广搜

 #include "iostream"
 #include "cstdio"
 #include "fstream"
 #include "sstream"
 #include "cstring"

 using namespace std;
 const int maxN = 3e4 + 1e2 ;
 struct Queue { int x , y , z ; } ;
 typedef long long QAQ ; 

 int dx[ ] = {  , - ,  ,  ,  ,  } ;
 int dy[ ] = {  ,  ,  ,  , - ,  } ;
 int dz[ ] = {  ,  , - ,  ,  ,  } ;

 int step[ maxN ] ;
 Queue Q[ maxN ] ;
 bool vis[  ][  ][  ] ;
 char map[  ][  ][  ] ;

 int L , R , C ;
 int start_x , start_y , start_z , des_x , des_y , des_z ;
 //QAQ Ans ;

 void Init ( ) {
         memset ( vis , false , sizeof ( vis ) ) ;
     memset ( step ,  , sizeof ( step ) ) ;
 } 

 inline bool Check ( const int x_x , const int y_y , const int z_z ) {return ( x_x == des_x && y_y == des_y && z_z == des_z ) ? true : false ; }
 int BFS ( ) {
     int Head =  , Tail =  ;
     Q[ Tail ].x = start_x ;
         Q[ Tail ].y = start_y ;
         Q[ Tail ].z = start_z ;
     while ( Head <= Tail ) {
         for ( int i= ; i< ; ++i ) {
             int xx = Q[ Head ].x + dx[ i ] ;
             int yy = Q[ Head ].y + dy[ i ] ;
             int zz = Q[ Head ].z + dz[ i ] ;
             if( !vis[ xx ][ yy ][ zz ] && ( map[ xx ][ yy ][ zz ] == '.'  ) && xx >=  && xx < L && yy >=  && yy < R && zz >=  && zz < C ) {
                 vis[ xx ][ yy ][ zz ] = true ;
                 Q[ ++Tail ].x = xx ;
                 Q[ Tail ].y = yy ;
                 Q[ Tail ].z = zz ;
                 step [ Tail ] = step[ Head ] +  ;
                 if ( Check ( xx , yy , zz ) ) return step[ Tail ] ;
             }
         }
         ++ Head ;
     }
     return false ;
 }

 void Scan ( ) {
         for ( int i= ; i<L ; ++i , getchar ( ) ){
         for ( int j= ; j<R ; ++j , getchar ( ) ){
                 for ( int k= ; k<C ; ++k ) {
                 map[ i ][ j ][ k ] = getchar ( ) ;
                 if ( map[ i ][ j ][ k ] == 'S' ) {
                     start_x = i ;
                                         start_y = j ;
                                         start_z = k ;
                                 }
                                 else if ( map[ i ][ j ][ k ] == 'E' ) {
                                         map[ i ][ j ][ k ] = '.' ;
                                         des_x = i ;
                                         des_y = j ;
                                         des_z = k ;
                                 }
             }
                 }
         }
 }

 inline void Print ( int temp ) {
         if( temp ) printf ( "Escaped in %d minute(s).\n" , temp ) ;
     else printf ( "Trapped!\n" ) ;
 }

 int main ( ) {
     while ( scanf ( "%d %d %d\n " , &L , &R , &C ) ==  && L && R && C ) {
             Init ( ) ;
             Scan ( );
             Print ( BFS( ) ) ;
     }
     return  ;
 }

2016-10-19 18:50:40

(完)