Gray Code

------QUESTION-----

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.

------SOLUTION-----

class Solution {public:    vector<int> grayCode(int n) {        vector<int> result;        int size = 1 << n;        for (int i =0; i< size; i++)        {            result.push_back(getGrayCode(i));        }        return result;    }    int getGrayCode(int binary)    {        return ((binary >> 1)^binary);    }};