Are the red bricks covering the ground?
Yes, the bricks are covering the ground.
    src        edge_attr  dst
0     0   to the left of    1
1     0   to the left of    9
2     1  to the right of    0
3     1   to the left of    9
4     2      standing at    9
5     2   to the left of    7
6     2  to the right of   18
7     2  to the right of    5
8     3   to the left of    9
9     3   to the left of   11
10    4   to the left of    9
11    5      standing at    9
12    5   to the left of    7
13    5  to the right of   18
14    5   to the left of    2
15    6   to the left of    7
16    6  to the right of   18
17    6      standing at    9
18    7  to the right of   18
19    7      standing at    9
20    7  to the right of    6
21    7  to the right of    5
22    7  to the right of    2
23    8   to the left of   11
24    8   to the left of    9
25    9  to the right of    0
26    9  to the right of    1
27    9  to the right of   19
28    9  to the right of    3
29    9  to the right of    8
30    9  to the right of   16
31    9  to the right of   12
32    9  to the right of   17
33    9  to the right of    4
34   11  to the right of    3
35   11  to the right of    8
36   12   to the left of    9
37   13       covered by   14
38   14         covering   13
39   16   to the left of    9
40   17               in   15
41   17   to the left of    9
42   18   to the left of    5
43   18   to the left of    6
44   18   to the left of    7
45   18   to the left of    2
46   18      standing at    9
47   19   to the left of    9