POJ-2251 Dungeon Master bfs搜索

就是将普通的二维推广到三维，方向变成了六个。

代码如下：

#include <cstring>
#include <cstdio>
#include <cstdlib>
using namespace std;

int L, N, M, sx, sy, sz;
 
struct Node
{
    int x, y, z, t;    
}e[100005], pos;

int front, tail, dir[6][3] ={
    0, 1, 0,
    0, -1, 0,
    1, 0, 0,
    -1, 0, 0,
    0, 0, 1, 
    0, 0, -1
};  // 六个方向，三个坐标 

char G[35][35][35];

bool judge(int x, int y, int z)
{
    if (x < 1 || x > N || y < 1 || y > M || z < 1 || z > L) {
        return false;
    }    
    else {
        return true;
    }
}

int bfs()
{
    int xx, yy, zz;
    front = 0;
    tail = 1;
    e[tail].x = sx, e[tail].y = sy;
    e[tail].z = sz,e[tail].t = 0;
    while (front != tail) {
        pos = e[++front];
        for (int i = 0; i < 6; ++i) {
            xx = pos.x + dir[i][0];
            yy = pos.y + dir[i][1];
            zz = pos.z + dir[i][2];
            if (judge(xx, yy, zz)) {
                if (G[zz][xx][yy] == '.') {
                    ++tail;
                    e[tail].x = xx, e[tail].y = yy;
                    e[tail].z = zz, e[tail].t = pos.t + 1;        
                    G[zz][xx][yy] = '#';
                }
                else if (G[zz][xx][yy] == 'E') {
                    return pos.t + 1;
                }
            }
        }
    }
    return -1;
}

int main()
{
    int flag, ans;
    while (scanf("%d %d %d", &L, &N, &M), L|N|M) {
        flag = 0;
        for (int i = 1; i <= L; ++i) {
            for (int j = 1; j <= N; ++j) {
                scanf("%s", G[i][j]+1);
                for (int k = 1; k <= M && !flag; ++k) {
                    if (G[i][j][k] == 'S') {
                        sx = j, sy = k, sz = i;
                        G[i][j][k] = '#';
                        flag = 1;
                        break;
                    }
                }
            }
        }
        ans = bfs();
        if (ans == -1) {
            printf("Trapped!\n");
        }
        else {
            printf("Escaped in %d minute(s).\n", ans);
        }
    }
    return 0;        
}