#124
Analyze Reversi
| Difficulty: | Hard |
| Topics: | game |
Reversi is normally played on an 8 by 8 board.
In this problem, a 4 by 4 board is represented
as a two-dimensional vector
with black, white, and empty pieces represented
by ‘b, ‘w, and ‘e, respectively.
Create a function that accepts
a game board and color as arguments,
and returns a map of legal moves for that color.
Each key should be the coordinates of a legal move,
and its value a set of the coordinates
of the pieces flipped by that move.
Board coordinates should be as in calls to get-in.
For example, [0 1] is the topmost row,
second column from the left.
 | (= {[1 3] #{[1 2]}
[0 2] #{[1 2]}
[3 1] #{[2 1]}
[2 0] #{[2 1]}}
(__ '[[e e e e]
[e w b e]
[e b w e]
[e e e e]] 'w)) |
| (= {[3 2] #{[2 2]}
[3 0] #{[2 1]}
[1 0] #{[1 1]}}
(__ '[[e e e e]
[e w b e]
[w w w e]
[e e e e]] 'b)) |
| (= {[0 3] #{[1 2]}
[1 3] #{[1 2]}
[3 3] #{[2 2]}
[2 3] #{[2 2]}}
(__ '[[e e e e]
[e w b e]
[w w b e]
[e e b e]] 'w)) |
| (= {[0 3] #{[2 1] [1 2]}
[1 3] #{[1 2]}
[2 3] #{[2 1] [2 2]}}
(__ '[[e e w e]
[b b w e]
[b w w e]
[b w w w]] 'b)) |
| (= {[0 3] #{[2 1] [1 2]}
[1 3] #{[1 2]}
[2 3] #{[2 1] [2 2]}}
(__ '[[e e w e]
[b b w e]
[b w w e]
[b w w w]] 'b)) |