Key Task

#include <iostream>
#include <cstring>
#include <cstdio>
#include <queue>
using namespace std;
int n, m, t;
char map[100][100];
bool f[1029][100][100];
int dir[] = {0, 1, 0, -1, 0};
int sum[100];
struct node {
    int x, y;
    int temp;
    __int64 w;
};
int bfs(node x)
{
    queue<node>q;
    q.push(x);
    node a, b;
    while (!q.empty()) {
        a = q.front(); q.pop();
        for (int i = 0; i < 4; i++) {
            b = a;
            b.x += dir[i];
            b.y += dir[i + 1];
            if (b.x < 0 || b.x >= n || b.y < 0 || b.y >= m)continue;
            if (map[b.x][b.y] == '#')continue;
            // if (b.temp >= t)return -1;
            if (map[b.x][b.y] == 'b' || map[b.x][b.y] =='y' || map[b.x][b.y] == 'r' || map[b.x][b.y] == 'g') {
                b.w|=(1<<(sum[map[b.x][b.y] - 'a']));
            }
            if (map[b.x][b.y] == 'B' || map[b.x][b.y] =='Y' || map[b.x][b.y] == 'R' || map[b.x][b.y] == 'G') {
                if (!(b.w & (1<<sum[map[b.x][b.y] - 'A'])))continue;
            }
            if (f[b.w][b.x][b.y] != 0)continue;
            b.temp++;
            f[b.w][b.x][b.y] = true;

            if (map[b.x][b.y] == 'X') {

                //  if (b.temp >= t)return -1;
                return b.temp;
            }
            q.push(b);
        }
    }
    return -1;
}
int main()
{
    node a;
    sum['B'-'A']=0,sum['Y'-'A']=1,sum['R'-'A']=2,sum['G'-'A']=3;
    while (cin >> n >> m) {
         if(n==m&&m==0)break;
        memset(f, 0 , sizeof(f));
        for (int i = 0; i < n; i++)
            for (int j = 0; j < m; j++) {
                cin >> map[i][j];
                if (map[i][j] == '*') {
                    a.x = i;
                    a.y = j;
                    a.w = 0;
                    a.temp = 0;
                }
            }
        int c = bfs(a);
        if (c != -1)
            cout << "Escape possible in " << c << " steps." << endl;
        else
            cout << "The poor student is trapped!" << endl;
        //cout << bfs(a) << endl;
    }
    return 0;
}