DIJKSTRA

Point Dijkstra(short r0, short r1, short c0, short c1, MapCell (*map)[MAP_WIDTH + 2], short att, short &distance, short (*dir)[2])
{
    short dist[MAP_HEIGHT + 2][MAP_WIDTH + 2];
    fill(dist[0], dist[0] + (MAP_HEIGHT + 2) * (MAP_WIDTH + 2), 999);
    dist[r0][c0] = 0;
    short parent[MAP_HEIGHT + 2][MAP_WIDTH + 2];
    parent[r0][c0] = -1;
    short r, c;
    list<Point> node_list;
    Point pt;
    for (short i=1; i<=MAP_HEIGHT; ++i)
    {
        for (short k=1; k<=MAP_WIDTH; ++k)
        {
            if (map[i][k].type == STONE)
                continue;
            pt.row = i;
            pt.col = k;
            node_list.push_front(pt);
        }
    }
    while (!node_list.empty())
    {
        //get min node
        list<Point>::iterator i = node_list.begin(), m = node_list.begin();
        for (; i != node_list.end(); ++i)
        {
            if (dist[i->row][i->col] < dist[m->row][m->col])
                m = i;
        }
        pt = *m;
        node_list.erase(m);

        //relax each adjacent node
        for (short k=0; k<4; ++k)
        {
            r = pt.row + dir[k][ROW];
            c = pt.col + dir[k][COL];
            if (r <= 0 || r > MAP_HEIGHT || c <= 0 || c > MAP_WIDTH || map[r][c].type == STONE)
                continue;
            short t;
            if (map[r][c].type == PERVIOUS) t = 0;
            else if (map[r][c].type = BRICK) t = 2 / att;
            else t = 1;
            if (dist[r][c] > dist[pt.row][pt.col] + t + 1)
            {
                dist[r][c] = dist[pt.row][pt.col] + t + 1;
                parent[r][c] = k;
            }
        }
    }
    distance = dist[r1][c1];
    r = r1;
    c = c1;
    short k = -1;
    while (parent[r][c] != -1)
    {
        assert(r >= 0 && r <= MAP_HEIGHT + 1 && c >= 0 && c <= MAP_WIDTH + 1);
        k = parent[r][c];
        r -= dir[k][ROW];
        c -= dir[k][COL];
    }
    if (k == -1)
        r = c = -1;
    else
    {
        r += dir[k][ROW];
        c += dir[k][COL];
    }
    pt.row = r;
    pt.col = c;
    return pt;
}