Python 刷Leetcode题库，顺带学英语单词（49）

Examples:
Input: 1
Output: true
Input: 0
Output: false
Input: 4
Output: true
Input: 64
Output: false

>>> PowerOfTwo = lambda n:bin(n).count('1')==1
>>> PowerOfTwo(1)
True
>>> PowerOfTwo(0)
False
>>> PowerOfTwo(4)
True
>>> PowerOfTwo(64)
True
>>> 

Examples:
Input: 27
Output: true
Input: 0
Output: false
Input: 9
Output: true
Input: 45
Output: false

>>> PowerofThree = lambda n:bin(int(n**(2/3))).count('1')==1
>>> PowerofThree(27)
True
>>> PowerofThree(0)
False
>>> PowerofThree(9)
True
>>> PowerofThree(45)
False