python:实现格雷码序列算法
def gray_code(bit_count: int) -> list:
"""
Takes in an integer n and returns a n-bit
gray code sequence
An n-bit gray code sequence is a sequence of 2^n
integers where:
a) Every integer is between [0,2^n -1] inclusive
b) The sequence begins with 0
c) An integer appears at m