Leetcode 89 Gray Code

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 0.

For example, given n = 2, return 

[0,1,3,2]

. Its gray code sequence
is:

00 - 0
01 - 1
11 - 3
10 - 2

Note:

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

For example, 

[0,2,3,1]

 is also a valid gray code sequence according to the above definition.

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

public class Solution {
public List<Integer> grayCode(int n) {
List<Integer> result = new LinkedList<>();
for (int i = 0; i < 1<<n; i++) result.add(i ^ i>>1);
return result;
}
}

grey 即是格雷码

比如说四位格雷码

0 对应0000

1 对应0001 = 1 ^ 1/2

3 对应0010 = 2 ^ 2/2 = 0010 ^ 0001

....