Gray Code Java Solutions

The gray code is a binary numeral system where the successive values are 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 0.

For example, given n = 2, return [0,1,3,2] . Its gray code sequence is:

00-001-111-310-2

Note:
For a given n, a gray code sequence is not uniquely defined.

For example, was [0,2,3,1] also a valid gray code sequence according to the above definition.

For now, the judge are able to judge based on one instance of gray code sequence. Sorry about that.

1  Public classSolution {2      PublicList<integer> Graycode (intN) {3list<integer> ans =NewArraylist<integer>();4         intLen = (int) Math.pow (2, n);5          for(inti = 0; i< Len; i++){6Ans.add (i^ (i>>1) ;//According to the solution of the mathematical formula. G (n) = (b (n)/2) XOR B (n).7         }8         returnans;9     }Ten}

Binary number transcoding Gray code

(assuming that the value of binary 0 is 0 of the Gray code)

G: Gray code B: binary Code

G (n) = (b (n)/2) XOR B (n).

Take three-bit as an example:

000^000-->000

001^000-->001

010^001-->011

011^001-->010

100^010-->110

101^010-->111

110^011-->101

111^011-->100

Solution Two: recursion is available. Later in the summary.

Reference Posts:

http://blog.csdn.net/makuiyu/article/details/44926463

Http://www.cnblogs.com/peihao/p/5269151.html (the second post described is still not clear enough)

Gray Code Java Solutions