UVa 532 - Dungeon Master

BFS ~不解释。

代码如下：

#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdlib>
#include <cstdio>
#include <cmath>
using namespace std;
const int MAXSIZE = 1000003;
int l, r, c, fl, fr, fc, dis[MAXSIZE];
int p1[6] = {1, -1, 0, 0, 0, 0};
int p2[6] = {0, 0, 1, -1, 0, 0};
int p3[6] = {0, 0, 0, 0, 1, -1};
char a[31][31][31];
bool vis[31][31][31];
struct Path
{
    int x, y, z;
} path[MAXSIZE];
int bfs()
{
    dis[1] = 0;
    path[1].x = fc;
    path[1].y = fr;
    path[1].z = fl;
    memset(vis, false, sizeof(vis));
    int front = 1, rear = 2;
    while(front < rear)
    {
        for(int i=0; i<6; i++)
        {
            int xx = path[front].x + p1[i];
            int yy = path[front].y + p2[i];
            int zz = path[front].z + p3[i];
            if(xx >= 0 && xx < c
             &&yy >= 0 && yy < r
             &&zz >= 0 && zz < l
             &&a[zz][yy][xx] != '#')
            {
                if(a[zz][yy][xx] == 'E')
                    return dis[front] + 1;
                if(a[zz][yy][xx] == '.' && !vis[zz][yy][xx])
                {
                    vis[zz][yy][xx] = true;
                    dis[rear] = dis[front] + 1;
                    path[rear].x = xx;
                    path[rear].y = yy;
                    path[rear].z = zz;
                    ++rear;
                }
            }
        }
        ++front;
    }
    return 0;
}
int main()
{
#ifdef test
    freopen("sample.txt", "r", stdin);
#endif
    int num;
    while(scanf("%d%d%d", &l, &r, &c), l&&r&&c)
    {
        memset(a, 0, sizeof(a));
        for(int i=0; i<l; i++)
        {
            for(int j=0; j<r; j++)
            {
                getchar();
                for(int k=0; k<c; k++)
                {
                    scanf("%c", &a[i][j][k]);
                    if(a[i][j][k] == 'S')
                    {
                        fl = i;
                        fr = j;
                        fc = k;
                    }
                }
            }
            getchar();
        }
        num = bfs();
        if(num)
            printf("Escaped in %d minute(s).\n", num);
        else
            puts("Trapped!");
    }
    return 0;
}