[leetcode]Gray Code @ Python

原题地址:https://oj.leetcode.com/problems/gray-code/

题意:

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.

解题思路:格雷码的生成,采用数学的方法。

代码:

class Solution:
    # @return a list of integers
    def grayCode(self, n):
        res=[]
        size=1<<n
        for i in range(size):
            res.append((i>>1)^i)
        return res

 

posted @ 2014-06-12 13:33  南郭子綦  阅读(2675)  评论(0编辑  收藏  举报