Bob and Ann invited their friends Diana and Cindy over for a cookout. On the
menu were grilled marinated beef cubes and four kinds of vegetables --
mushrooms, onions, peppers, and tomatoes -- which were put onto skewers. The
first skewer that each person made had three beef cubes and one piece of three
kinds of vegetables -- each person disliked a different vegetable and omitted it
from his or her skewer. The six pieces can be numbered 1 to 6 from the handle to
the point of the skewer. Can you tell what item each person had in each
position?

1. No kebab had two beef cubes right next to each other.
2. No one's beef cubes were in the same three positions as anyone else's.
3. One shish kebab's first three items (numbers 1, 2, and 3 respectively) were
   beef, pepper, and mushroom; this wasn't Diana's. 
4. One skewer had beef cubes in positions 1, 3, and 5, and a tomato wedge in
   position 6. 
5. Bob, who loves onions and included a chunk on his skewer, had vegetables in
   both positions 4 and 5. 
6. On the four kebabs, the items in position 5 were beef, mushroom, onion and
   tomato. 
7. Each onion chunk was immediately between two beef cubes.
8. No pepper was immediately between two beef cubes.
9. Cindy can't stand mushrooms and left them off her skewer.
10 At least two kebabs had the same vegetable in the same position at least once.

Determine: Person - 1 - 2 - 3 - 4 - 5 - 6 - Veggie skipped 

Two (correct) versions are requested.
First, an elementary program, easy to write and to read;
second, an efficient program, inducing a fast computation.