poj 2251

三维的dfs。

#include <iostream>
#include <cstring>

using namespace std;

struct q {
	int x;
	int y;
	int z;
}q[30000];

int length[30000];  
int xx[]={1,-1,0,0,0,0};  
int yy[]={0,0,0,0,-1,1};  
int zz[]={0,0,-1,1,0,0};  
bool dis[40][40][40];  
char map[40][40][40];  
int l,r,c,sx,sy,sz;

int bfs() {
	int rear, front, dx, dy, dz, i;
	memset(dis, false, sizeof(dis));
	memset(length, 0, sizeof(length));
	
	q[0].x = sx;
	q[0].y = sy;
	q[0].z = sz;
	front = rear = 0;
	while(front <= rear) {
		for(i=0; i<6; i++) {
			dx = q[front].x + xx[i];
			dy = q[front].y + yy[i];
			dz = q[front].z + zz[i];
			
			if(!dis[dx][dy][dz] && (map[dx][dy][dz]=='.' || map[dx][dy][dz]=='E') && dx>=0 && dx<l && dy>=0 && dy<r && dz>=0 && dz<c) {
				dis[dx][dy][dz] = true;
				q[++rear].x = dx;
				q[rear].y = dy;
				q[rear].z = dz;
				length[rear] = length[front] + 1;
				if(map[dx][dy][dz] == 'E')	return length[rear];
			}
		}
		front++;
	}
	
	return 0;
}

int main() {
	int i, j, k, key;
	while(~scanf("%d%d%d\n", &l, &r, &c)) {
		if(l==0 && r==0 && c==0)	break;
		
		for(i=0; i<l; i++,getchar())
			for(j=0; j<r; j++,getchar())
				for(k=0; k<c; k++) {
					scanf("%c", &map[i][j][k]);
					if(map[i][j][k] == 'S')
						sx=i, sy=j, sz=k;
				}
		key = bfs();
		if(key) printf("Escaped in %d minute(s).\n",key);  
        else printf("Trapped!\n");
	}
	
	return 0;
}