11 lines
159 B
Prolog
11 lines
159 B
Prolog
|
to_gray(N, G) :-
|
||
|
|
N0 is N >> 1,
|
||
|
|
G is N xor N0.
|
||
|
|
|
||
|
|
from_gray(G, N) :-
|
||
|
|
( G > 0
|
||
|
|
-> S is G >> 1,
|
||
|
|
from_gray(S, N0),
|
||
|
|
N is G xor N0
|
||
|
|
; N is G ).
|