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.

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public class S
4000
olution {  

    public List<Integer> grayCode(int n) {  

        List<Integer> res = new ArrayList<Integer>();     

        int i = 1<<n;  

        int j = 0;  

        while(j<i){  

            res.add((j>>1)^j);  

            j++;  

        }  

        return res;  

    }  

  

}

原文链接http://blog.csdn.net/crazy__chen/article/details/46434367