# Friends and Enemies

Here is a short puzzle I made:

There are 10 people arranged in a row, and each of them has a friend and an enemy also present in the row. Your goal is to identify the friend and enemy of each person.

Friends:

A friend relation is two-sided, that is, if (1)'s friend is (2), then (2)'s friend must be (1).

Enemies:

An enemy relation is one-sided, that is, if (1)'s enemy is (2), then (2)'s enemy can be any other person, maybe (1).

Extra Facts about friends and enemies:

• No two people can have the same friend or the same enemy.
• The friend and enemy of a person must be two distinct people.
• A person cannot be the enemy or friend of themselves.

Directions:

• 'R': Both the friend and the enemy are to the right of that person.
• 'L': Both the friend and the enemy are to the left of that person.
• 'O': The friend and the enemy are in opposite sides of that person.
It is not given which one is to the left and which one is to the right.

The Puzzle:

PERSON A B C D E F G H I J
DIRECTIONS R O L O L O R R O L
FRIENDS
ENEMIES

Extra Information required to guarantee a unique solution:

It is also known that A's enemy is not E.

• Is A right of B or B right of A? Commented Jan 31, 2023 at 21:48
• Oh B is to the right of A, I didn't see the need to clarify that as it is known the friend and enemy are to the right of A. Commented Feb 1, 2023 at 1:19
• Now that you say it, that is indeed obvious. Commented Feb 1, 2023 at 19:00