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 n == 2^x n==2x.

Example 1:

Input: n = 1
Output: true
Explanation: 2 0 = 1 2^0 = 1 20=1

Example 2:

Input: n = 16
Output: true
Explanation: 2 4 = 16 2^4 = 16 24=16

Example 3:

Input: n = 3
Output: false

Constraints:

• − 2 31 < = n < = 2 31 − 1 -2^{31} <= n <= 2^{31} - 1 −231<=n<=231−1

From: LeetCode

Link: 231. Power of Two

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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;
}