(BFS搜索)【POJ 2251】Dungeon Master

题目链接：http://poj.org/problem?id=2251

现在还不太分的清什么时候用BFS什么时候用DFS。。总感觉DFS好敲一点所以刚开始用DFS写的，估计还写错了，一直WA。没什么坑，输入的时候注意吸收那个换行就好了。

/*
* @Author: Samson
* @Date:   2018-04-24 11:07:06
* @Last Modified by:   Samson
* @Last Modified time: 2018-04-24 14:15:14
*/
//   @URL : http://poj.org/problem?id=2251
#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<queue>
#include <cstdlib>
#define INF 0x3f3f3f3f
using namespace std;
typedef long long LL;
const int MAXN = 30+10;

int l,r,c,vis[MAXN][MAXN][MAXN],sl,sr,sc;
int nxt[] = {0,0,1,0,0,-1,0,0};
char a[MAXN][MAXN][MAXN];
struct node
{
	int lev,row,col,cur;
}tmp,p;

void init()
{
	for(int i = 1; i <= l; ++i)
	{
		for(int j = 1; j <= r; ++j)
			scanf("%s",a[i][j]+1);
		getchar();
	}
	for(int i = 1; i <= l; ++i)
		for(int j = 1; j <= r; ++j)
			for(int k = 1; k <= c; ++k)
				if(a[i][j][k] == 'S')
					sl = i,sr = j,sc = k;
	memset(vis,0,sizeof vis);
	vis[sl][sr][sc] = 1;
}

void bfs()
{
	queue<node> que;
	tmp.lev = sl;	tmp.row = sr;	tmp.col = sc;	tmp.cur = 0;
	que.push(tmp);
	while(!que.empty())
	{
		tmp = que.front();
		que.pop();
		for(int i = 0; i < 6; ++i)
		{
			p.lev = tmp.lev+nxt[i];
			p.row = tmp.row+nxt[i+1];
			p.col = tmp.col+nxt[i+2];
			p.cur = tmp.cur;
			if(a[p.lev][p.row][p.col]=='#' || p.lev<1 || p.lev>l || p.row<1 || p.row>r || p.col<1 || p.col>c)
				continue;
			if(!vis[p.lev][p.row][p.col])
			{
				vis[p.lev][p.row][p.col] = 1;
				++p.cur;
				if(a[p.lev][p.row][p.col] =='E')
				{
					cout<<"Escaped in "<<p.cur<<" minute(s).\n";
					return;
				}
				que.push(p);
			}
		}
	}
	cout<<"Trapped!\n";
}

int main(void)
{
	while(cin>>l>>r>>c,l+r+c)
	{
		init();
		bfs();
	}
	return 0;
}