Leetcode Gray Code

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.

Test Instructions: Find the Graycode code with a length of n .

Idea: Regular question: starting from the No. 0, the first gray code is: (i>>1) ^i

public class Solution {public    list<integer> graycode (int n) {        list<integer> List = new arraylist< Integer> ();        if (n = = 0) {            list.add (0);            return list;        }                int num = 1 << n;        int cur = 0;        while (cur < num)             List.add ((cur >> 1) ^ (cur++));        return list;      }}

Leetcode Gray Code