> 附代码：
> /*
>   Name: PKU_2225_Asteroid!_SS_F
>   Copyright: PRIVATE!!!
>   Author: LONGIXAOZHI
>   Date: 28-08-09 14:37
>   Description: 三维空间的迷宫问题 三维广搜 
>   宇宙空间与许多的小行星，从一个空位置出发去一个地方，要求找到最短的路径，没有输出NO ROUT!
>   因为只可以走上下左右前后，因此，
>   方向坐标为step[6][3]= { {1,0,0},{-1,0,0},{0,1,0},{0,-1,0},{0,0,1},{0,0,1}};
>   记录路径的长度 dist[x][y][z]; 记录走到空间（x,y,z); dist[x][y][z]=0; 表示该点已经走过；
>   定义一个map[x][y][z]; 记录空间的状态,因为只有能走和不能走两个状态，因此可定义为一个bool数组；
>   bests 定义最短的距离；单位为1;
> */
> #include<iostream>
> #include<string>
> #include<queue>
> using namespace std;
> const int maxn=10;
> bool map[maxn][maxn][maxn];  
> int dist[maxn][maxn][maxn];
> int step[6][3]={{1,0,0},{-1,0,0},{0,1,0},{0,-1,0},{0,0,1},{0,0,-1}};
> struct Coor
> {
> 	int x,y,z;
> }s,e;
> int n,bests;
> 
> void BFS()
> {
> 	memset(dist,0,sizeof(dist));
> 	dist[s.x][s.y][s.z]=0;
> 	queue<int> Q;
> 	Q.push(s.x); Q.push(s.y); Q.push(s.z);
> 	Coor t1,t2;
> 	while(!Q.empty())
> 	{
> 		t1.x=Q.front(); Q.pop();
> 		t1.y=Q.front(); Q.pop();
> 		t1.z=Q.front(); Q.pop();
> 		if(t1.x == e.x && t1.y == e.y && t1.z == e.z)
> 		{
> 			if(dist[t1.x][t1.y][t1.z] < bests) bests=dist[t1.x][t1.y][t1.z];
> 		}
> 		for(int k=0; k<6; k++)
> 		{
> 			t2.x= t1.x + step[k][0];
> 			t2.y= t1.y + step[k][1];
> 			t2.z= t1.z + step[k][2]; 
> 			if(t2.x >= n || t2.x < 0 || t2.y >= n || t2.y < 0 || t2.z >= n || t2.z < 0) 
> 				continue;
> 			if(dist[t2.x][t2.y][t2.z] != 0 || map[t2.x][t2.y][t2.z] == 0 ) 
> 				continue;
> 			
> 			dist[t2.x][t2.y][t2.z]= dist[t1.x][t1.y][t1.z] + 1;
> 			Q.push(t2.x); Q.push(t2.y); Q.push(t2.z);
> 		}
> 	}
> }
> 
> int main()
> {   
> 	char str[maxn]; int i,j,k;
> 	while(scanf("%s%d",&str,&n)!=EOF)
> 	{
> 		for( k=0; k<n; k++)          
> 		{  
> 			for( i=0; i<n; i++)      
> 			{    
> 				scanf("%s",str);
> 				for( j =0; j<n; j++) 
> 				{   
> 					if(str[j] == 'X') 
> 						map[i][j][k]= 0;
> 					else 
> 						map[i][j][k]= 1;
> 				}
> 			}
> 		}
> 		scanf("%d%d%d",&s.x,&s.y,&s.z);
> 		scanf("%d%d%d",&e.x,&e.y,&e.z);
> 		scanf("%s",str);
> 
> 		bests=1001;
> 		BFS();
> 		if(bests == 1001) 
> 			cout<<"NO ROUTE"<<endl;
> 		else
> 		  cout<<n<<" "<<bests<<endl;
> 	}
> 	return 0;
> }
> /*
> Sample Input
> START 1
> O
> 0 0 0
> 0 0 0
> END
> 
> START 3
> OOO
> OOO
> OOO
> XXX
> XXX
> XXO
> OOO
> OOO
> OOO
> 0 0 0
> 0 0 2
> END
> 
> START 3
> OOO
> OOO
> OOO
> XXX
> XXO
> XXX
> OOO
> OOO
> OOO
> 0 0 0
> 0 0 2
> END
> 
> START 3
> XXX
> XXX
> XXX
> OOO
> OOO
> OOO
> XXX
> XXX
> XXX
> 0 0 1
> 2 2 1
> END
> 
> START 5
> OOOOO
> OOOOO
> OOOOO
> OOOOO
> OOOOO
> OOOOO
> OOOOO
> OOOOO
> OOOOO
> OOOOO
> XXXXX
> XXOXX
> XXXXX
> XXXXX
> XXXXX
> OOOOO
> OOOOO
> OOOOO
> OOOOO
> OOOOO
> OOOOO
> OOOOO
> OOOOO
> OOOOO
> OOOOO
> 0 0 0
> 4 4 4
> END
> 
> Sample Output
> 
> 1 0
> 3 10
> NO ROUTE
> 3 4
> NO ROUTE
> 
> Source
> 
> South Central USA 2001
> */
>