Kata Reversi

Source: http://codingdojo.org/cgi-bin/wiki.pl?KataReversi

Difficulty: Easy

Problem Description

Reversi is a board game for two players. More information can be found on Wikipedia. This Kata is to write a program that takes a current board position together with information about whose turn it is, and returns a list of the legal moves for that player. A move is only legal if it results in at least one of the opponent's counters being flipped.

Suggested Test Cases

. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . B W . . .
. . . W B . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
B

(A "." indicates an empty square. A "B" indicates a black piece and a "W" represents a white piece. The trailing "B" indicates that it is black's turn)

You could either output the possible moves as co-ordinates (columns labelled A - H, rows labelled 1 - 8 starting from top left hand corner) like this:

[C5, D6, E3, F4]

or graphically like this:

. . . . . . . .
. . . . . . . .
. . . . 0 . . .
. . . B W 0 . .
. . 0 W B . . .
. . . 0 . . . .
. . . . . . . .
. . . . . . . .
B