LeetCode 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.

思路：规律题：从第0个开始，第i个gray code为：(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

原文：http://blog.csdn.net/u011345136/article/details/45021395