Poj 2251 Dungeon Master

题目大意：给出一个三维空间的地牢，要求输出从起点到终点所用的最短时间。每次移动耗时一分钟。

思路：BFS，只是将二维空间扩展到三维空间，方向由原先的四个增加的六个 而已。

#include <iostream>
using namespace std;
#include <deque>
#include <stdio.h>
int map[40][40][40];
int flag[40][40][40];
int l,r,c;
int s1,s2,s3,e1,e2,e3;
deque<int> dem1,dem2,dem3;
int BFS() {
	int i,j,k,ctr,size;
	int x,y,z,sign;

	ctr=0;
	x=s1;
	y=s2;
	z=s3;
	sign=0;
	flag[x][y][z]=1;
	dem1.push_back(x);
	dem2.push_back(y);
	dem3.push_back(z);
	while (!dem1.empty()) {
		size=dem1.size();
		while (size--) {
			x=dem1.front();
			dem1.pop_front();
			y=dem2.front();
			dem2.pop_front();
			z=dem3.front();
			dem3.pop_front();
			if (x==e1&&y==e2&&z==e3) {
				sign=1;
				break;
			}
			if (x-1>=1&&map[x-1][y][z]=='.'&&flag[x-1][y][z]==0) {
				flag[x-1][y][z]=1;
				dem1.push_back(x-1);
				dem2.push_back(y);
				dem3.push_back(z);
			}
			if (x+1<=l&&map[x+1][y][z]=='.'&&flag[x+1][y][z]==0) {
				flag[x+1][y][z]=1;
				dem1.push_back(x+1);
				dem2.push_back(y);
				dem3.push_back(z);
			}
			if (y-1>=1&&map[x][y-1][z]=='.'&&flag[x][y-1][z]==0) {
				flag[x][y-1][z]=1;
				dem1.push_back(x);
				dem2.push_back(y-1);
				dem3.push_back(z);
			}
			if (y+1<=r&&map[x][y+1][z]=='.'&&flag[x][y+1][z]==0) {
				flag[x][y+1][z]=1;
				dem1.push_back(x);
				dem2.push_back(y+1);
				dem3.push_back(z);
			}
			if (z-1>=1&&map[x][y][z-1]=='.'&&flag[x][y][z-1]==0) {
				flag[x][y][z-1]=1;
				dem1.push_back(x);
				dem2.push_back(y);
				dem3.push_back(z-1);
			}
			if (z+1<=c&&map[x][y][z+1]=='.'&&flag[x][y][z+1]==0) {
				flag[x][y][z+1]=1;
				dem1.push_back(x);
				dem2.push_back(y);
				dem3.push_back(z+1);
			}
		}
		if (sign==1)
			break;
		ctr++;
	}
	if (sign==1)
		return ctr;
	else 
		return 0;
}
int main()
{
	int i,j,k;
	int result;

	scanf("%d%d%d",&l,&r,&c);
	while (!(l==0&&r==0&&c==0)) {
		getchar();
		for (i=1;i<=l;i++) {
			for (j=1;j<=r;j++) {
				for (k=1;k<=c;k++) {
					flag[i][j][k]=0;
					scanf("%c",&map[i][j][k]);
					if (map[i][j][k]=='S') {
						s1=i;
						s2=j;
						s3=k;
					}
					if (map[i][j][k]=='E') {
						e1=i;
						e2=j;
						e3=k;
						map[i][j][k]='.';
					}
				}
				getchar();
			}
			getchar();
		}
		result=BFS();
		dem1.clear();
		dem2.clear();
		dem3.clear();
		if (result==0)
			printf("Trapped!\n");
		else 
			printf("Escaped in %d minute(s).\n",result);
		scanf("%d%d%d",&l,&r,&c);
	}
	return 0;
}