LeetCode //C - 231. Power of Two

231. 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 $n==2^x$.
 

Example 1:

Input: n = 1
Output: true
Explanation: $2^0=1$

Example 2:

Input: n = 16
Output: true
Explanation: $2^4=16$

Example 3:

Input: n = 3
Output: false

Constraints:

• $-2^{31}<=n<=2^{31}-1$

From: LeetCode
Link: 231. Power of Two

Solution:

Ideas:

1. Check if n is positive: The condition if (n <= 0) ensures that negative numbers and zero return false, since powers of two are always positive.
2. Bitwise check: The expression (n & (n - 1)) == 0 checks if n has exactly one bit set.

Code:

bool isPowerOfTwo(int n) {
    if (n <= 0) {
        return false;
    }
    return (n & (n - 1)) == 0;
}