Sixteen cabins are in a large forest, and each cabin is connected to
at least two of the other cabins by walking trails, as shown in the
diagram. Two cabins are said to be neighbours if they are
directly connected by a trail segment. After a big storm, each resident
walked to each of their neighbours houses to ask whether or not they had
lost power. In the diagram, the number on each cabin indicates the
number of its neighbours who still had power after the storm.
Sixteen cabins are arranged into a 4 by 4 grid. The cabins are labelled A through R, excluding I and O. They are labelled starting with A at the top left corner and then in order from left to right and row by row. Each cabin is connected by a trail to any cabin that is directly to its left, directly to its right, directly above it, directly below it, or diagonally below it and to its left.
For each cabin, the following table gives the cabin's neighbours and the number of its neighbours who still had power.
Cabin
Neighbours
Number of Neighbours with Power
A
B, E
2
B
A, C, E, F
2
C
B, D, F, G
3
D
C, G, H
2
E
A, B, F, J
2
F
B, C, E, G, J, K
4
G
C, D, F, H, K, L
4
H
D, G, L, M
3
J
E, F, K, N
3
K
F, G, J, L, N, P
4
L
G, H, K, M, P, Q
4
M
H, L, Q, R
2
N
J, K, P
2
P
K, L, N, Q
3
Q
L, M, P, R
2
R
M, Q
0
Determine which cabins still have power after the storm.
