The gray code is a binary numeral system where two successive values differ in only one bit.
Given a non-negative integer
n representing the total number of bits in the code, print the sequence of gray code. A gray code sequence must begin with
For example, given n =
[0,1,3,2]. Its gray code sequence is:
00 - 0 01 - 1 11 - 3 10 - 2
There might be multiple gray code sequences possible for a given n.
Return any such sequence.