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[Difficulty: Simple]

Given an integer and write a function to determine whether it is the power of 2.

Example 1:

Input:1
Output:true

Explanation: $2^0=1$

Example 2:

Input:16
Output:true

Explanation: $2^4=16$

Example 3:

Input:218
Output:false

• python3 implementation method 1:

class Solution:
    def isPowerOfTwo(self, n: int) -> bool:
        
        k = 0
        while True:
            if 2**k == n:
                return True
            elif 2**k > n:
                break
            k += 1
        return False

• python3 implementation method 2: bit operation

class Solution:
    def isPowerOfTwo(self, n: int) -> bool:
		return n > 0 and n & (n - 1) == 0

• Solution 1:
  

• Solution 2:bit operation
  

Tencent Selected Exercise 50 questions 231. 2 power.

1. Original content, reprint the source!
2. The above content is organized, and it is feasible for pro -testing. If you have any problems, please correct me, thank you ~~
3. Praise, collection, and welcome to reward, I play the piano, you listen ~~ haha!