Power of Two.cpp

/*
Power of Two
============

Given an integer n, return true if it is a power of two. Otherwise, return false.

An integer n is a power of two, if there exists an integer x such that n == 2x.

Example 1:
Input: n = 1
Output: true
Explanation: 20 = 1

Example 2:
Input: n = 16
Output: true
Explanation: 24 = 16

Example 3:
Input: n = 3
Output: false

Example 4:
Input: n = 4
Output: true

Example 5:
Input: n = 5
Output: false

Constraints:
-231 <= n <= 231 - 1

Follow up: Could you solve it without loops/recursion?
*/

class Solution
{
public:
  bool isPowerOfTwo(int n)
  {
    if (n <= 0)
      return false;
    return !(n & n - 1);
  }
};