View solution

column

A

B

C

D

E

F

G

H

I

J

row

1

F

D

O

E

M

A

P

E

D

O

2

N

R

E

S

D

R

O

I

V

D

3

U

U

S

S

N

P

S

S

O

D

4

C

E

I

N

O

Y

H

H

N

A

5

L

T

O

H

L

D

I

E

V

R

6

I

E

O

M

T

E

C

E

A

E

7

R

C

K

C

I

T

I

A

O

R

8

N

E

Z

S

E

A

E

N

L

R

• No two bulbs shine at each other, neither horizontally, vertically nor diagonally.
• Each side of the room has exactly two lit bulbs. On one side, the lit bulbs have exactly one unlit between them; two on another side; three and then four on the remaining sides.
• The only lit bulb adjacent to any corner of the room is adjacent to the north-east corner.
• The bulbs in rows 2, 4 and 5 and in column E are all duds.