pku 2251 Dungeon Master BFS

http://poj.org/problem?id=2251

很简单的求最短路径的BFS题目，才开始自己写了各DFS直接性TLE。。。

三维的，就是多加了两个方向罢了，再处理的时候就按i,j,k来；

View Code

#include <iostream>

#include <cstring>

#include <cstdio>

#include <queue>

#define maxn 33

using namespace std;



struct node

{

    int x,y,z;

    int len;

}s;

char map[maxn][maxn][maxn];

bool vt[maxn][maxn][maxn];

int l,r,c,ans;

bool flag;

int dir[6][3] = {{0,0,1},{0,0,-1},{0,1,0},{0,-1,0},{1,0,0},{-1,0,0}};

int bfs()

{

    int i;

    node t;

    queue<node>q;

    while (!q.empty()) q.pop();

    q.push(s);

    vt[s.x][s.y][s.z] = true;

    while (!q.empty())

    {

        node cur = q.front();

        q.pop();

        if (map[cur.x][cur.y][cur.z] == 'E')

        {

            return cur.len;

        }

        for (i = 0; i < 6; ++i)

        {

            t.x = cur.x + dir[i][0];

            t.y = cur.y + dir[i][1];

            t.z = cur.z + dir[i][2];

            if (t.x >= 0 && t.x < l && t.y >= 0 &&t.y < r && t.z >= 0 && t.z < c && map[t.x][t.y][t.z] != '#' && !vt[t.x][t.y][t.z])

            {

                vt[t.x][t.y][t.z] = true;

                t.len = cur.len + 1;

                q.push(t);

            }

        }

    }

    return -1;

}

int main()

{

    //freopen("in.txt","r",stdin);

    int i,j,k;

    while (scanf("%d%d%d",&l,&r,&c))

    {

        if (!l && ! r && !c) break;

        for (i = 0; i < l; ++i)

        {

            for (j = 0; j < r; ++j)

            {

                scanf("%s",map[i][j]);

                for (k = 0; k < c; ++k)

                {

                    if (map[i][j][k] == 'S')

                    {

                        s.x = i; s.y = j;

                        s.z = k; s.len = 0;

                    }

                }

            }

        }

        memset(vt,false,sizeof(vt));

        int l = bfs();

        if (l == -1)

        printf("Trapped!\n");

        else

        printf("Escaped in %d minute(s).\n",l);

    }

    return 0;

}