POJ 2251 Dungeon Master（三维空间bfs）

题意：三维空间求最短路，可前后左右上下移动。

分析：开三维数组即可。

#include<cstdio>
#include<cstring>
#include<queue>
using namespace std;
const int MAXN = 30 + 10;
char pic[MAXN][MAXN][MAXN];
bool vis[MAXN][MAXN][MAXN];
int sx, sy, sz;
int dr[] = {0, 0, 1, -1, 0, 0};
int dc[] = {1, -1, 0, 0, 0, 0};
int dz[] = {0, 0, 0, 0, 1, -1};
int L, R, C;
bool judge(int x, int y, int z){
    return x >= 0 && x < R && y >= 0 && y < C && z >= 0 && z < L;
}
int bfs(){
    queue<int> x, y, z, step;
    x.push(sx), y.push(sy), z.push(sz), step.push(0);
    vis[sz][sx][sy] = true;
    while(!x.empty()){
        int tmpx = x.front(); x.pop();
        int tmpy = y.front(); y.pop();
        int tmpz = z.front(); z.pop();
        int tmpstep = step.front(); step.pop();
        for(int i = 0; i < 6; ++i){
            int tx = tmpx + dr[i];
            int ty = tmpy + dc[i];
            int tz = tmpz + dz[i];
            if(judge(tx, ty, tz)){
                if(pic[tz][tx][ty] == 'E') return tmpstep + 1;
                if(pic[tz][tx][ty] != '#' && !vis[tz][tx][ty]){
                    vis[tz][tx][ty] = true;
                    x.push(tx);
                    y.push(ty);
                    z.push(tz);
                    step.push(tmpstep + 1);
                }
            }
        }
    }
    return -1;
}
int main(){
    while(scanf("%d%d%d", &L, &R, &C) == 3){
        if(!L && !R && !C) return 0;
        memset(vis, false, sizeof vis);
        for(int i = 0; i < L; ++i){
            for(int j = 0; j < R; ++j){
                scanf("%s", pic[i][j]);
                for(int k = 0; k < C; ++k){
                    if(pic[i][j][k] == 'S'){
                        sz = i, sx = j, sy = k;
                    }
                }
            }
        }
        int ans = bfs();
        if(ans == -1) printf("Trapped!\n");
        else printf("Escaped in %d minute(s).\n", ans);
    }
    return 0;
}