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2013
11-11

POJ 2251 Dungeon Master [解题报告] Java

Dungeon Master

问题描述 :

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?

输入:

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.

输出:

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!

样例输入:

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

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

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

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

0 0 0

样例输出:

Escaped in 11 minute(s).
Trapped!

解题代码:

//* @author: 
import java.util.*;

class  point {
    int x;
    int y;
    int z;
    int step;

  public point(int x,int y,int z,int step){
    this.x=x;
    this.y=y;
    this.z=z;
    this.step=step;
  }


 public int  getX(){
   return this.x;
 }
 
 public int getY(){
   return this.y;
 }

public int getZ(){
  return this.z;
 }

 public int getStep(){
   return this.step;
}
       
}

public class Main {
  //移动方向可以是上,下,左,右,前,后,六个方向
 static int dir[][] = {{1, 0, 0}, {0, 1, 0}, {0, 0, 1}, {-1, 0, 0}, {0, -1, 0}, {0, 0, -1}};
 char map[][][];//三维地图,有三层
 int R, L, C;

 public Main(char map[][][],int L,int R,int C){
    this.map=map;
    this.L=L;
    this.R=R;
    this.C=C;
}

int bfs(int x, int y, int z) {
    
    ArrayList queue=new ArrayList();

    queue.add(new point(x,y,z,0));
   
    while(queue.size()!=0) {
       
        for(int i = 0; i < 6; i++) {
            //队头元素出队;
             point head=queue.get(0);
            int a = head.x + dir[i][0];
            int b = head.y + dir[i][1];
            int c = head.z + dir[i][2];
            if(a >= 0 && a < L && b >= 0 && b < R && c >= 0 && c < C && map[a][b][c] == 'E')
                return head.step + 1;
            if(a >= 0 && a < L && b >= 0 && b < R && c >= 0 && c < C && map[a][b][c] != '#') {
                  //元素入队;
                queue.add(new point(a,b,c,head.step+1));
                
                map[a][b][c] = '#';
              
            }
        }
       queue.remove(0);
    }
    return -1;
}

 
 public static void main(String[] args){
  Scanner in = new Scanner(System.in);
    int a, b, c;
    int L1,R1,C1;
    while(in.hasNext()) {
       L1=in.nextInt();
       R1=in.nextInt();
       C1=in.nextInt();
       if(L1==0&&R1==0&&C1==0) break;
        a = b = c = 0;
  
        char map1[][][]=new char[L1][R1][C1];
   
        for(int i = 0; i < L1; i++)
          for(int j = 0; j < R1; j++){
           map1[i][j]=in.next().toCharArray();
           for(int k=0;k< C1;k++){
                if(map1[i][j][k] == 'S') {
                    a = i;
                    b = j;
                    c = k;
                }
            }
         }

       
        Main m=new Main(map1,L1,R1,C1);
        
        int sum = m.bfs(a, b, c);
        if(sum != -1)
            System.out.printf("Escaped in %d minute(s).\n", sum);
        else
            System.out.printf("Trapped!\n");
    }
   }
}