POJ 2251 Dungeon Master

题目:http://poj.org/problem?id=2251

题目的要求很简单，就是求个最短路

只不过二维的迷宫推广到了三维的迷宫而已

就是用BFS用到队列

话不多说，直接上代码，很好理解.

#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
#include <stack>
#include <queue>
using namespace std;
int m,n,p;
int sx,sy,sz,ex,ey,ez;
char map[31][31][31];
bool vis[31][31][31];
int dir[6][3]={{1,0,0},{-1,0,0},{0,1,0},{0,-1,0},{0,0,1},{0,0,-1}};//三维方向
struct node
{
    int x;
    int y;
    int z;
    int t;
}now,next;
bool check(int x,int y,int z)
{
    if(x>=0&&x<n&&y>=0&&y<m&&z>=0&&z<p)
    {
        return true;
    }
    return false;
}
int bfs()
{
    int fx,fy,fz;
    queue<node> q;
    now.x=sx;
    now.y=sy;
    now.z=sz;
    now.t=0;
    q.push(now);//把当前的位置压入队列
    while(!q.empty())
    {
        now=q.front();
        q.pop();
        if(now.x==ex&&now.y==ey&&now.z==ez)
        {
            return now.t;
        }
        for(int i=0;i<6;i++)
        {
            fx=now.x+dir[i][0];
            fy=now.y+dir[i][1];
            fz=now.z+dir[i][2];
            if(check(fx,fy,fz)&&map[fx][fy][fz]!='#'&&!vis[fx][fy][fz])
            {
                vis[fx][fy][fz]=true;
                next.x=fx;
                next.y=fy;
                next.z=fz;
                next.t=now.t+1;
                q.push(next);//把接下来的步骤压入队列
            }
        }
    }
    return 0;
}
int main()
{
    int time;
    //freopen("in.txt","r",stdin);
    while(scanf("%d%d%d",&p,&n,&m)!=EOF)
    {
        if(p==0&&m==0&&n==0)
            break;
        getchar();
        memset(vis,0,sizeof vis);
        for(int i=0;i<p;i++)
        {
            for(int j=0;j<n;j++)
            {
                for(int k=0;k<m;k++)
                {
                    cin>>map[j][k][i];
                    if(map[j][k][i]=='S')
                    {
                        sx=j;
                        sy=k;
                        sz=i;
                        map[j][k][i]='#';
                    }
                    else if(map[j][k][i]=='E')
                    {
                        ex=j;
                        ey=k;
                        ez=i;
                    }
                }
            }
        }
        time=bfs();
        if(time==0)
        {
            cout<<"Trapped!"<<endl;
        }
        else
        {
            cout<<"Escaped in "<<time<<" minute(s)."<<endl;
        }
    }
    return 0;
}