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 == 2x.

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

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?

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class Solution:
    def isPowerOfTwo(self, n: int) -> bool:
        val = 1
        while val < n:
            val *= 2
        return val == n

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func isPowerOfTwo(n int) bool {
	i := 1
	for i < n {
		i *= 2
	}
	return i == n
}