Introduction Link to heading

Given an integer, write a function to determine if it is a power of two.

Example 1:

Input: 1
Output: true
Explanation: 20 = 1

Example 2:

Input: 16
Output: true
Explanation: 24 = 16

Example 3:

Input: 218
Output: false

Solution Link to heading

Very simple solution

func isPowerOfTwo(n int) bool {
    for i := n; i > 0; i >>= 1 {
        if (i & 1) > 0 {
            if i == 1 {
                return true
            } else if i > 1 {
                return false
            }
        }
    }
    return false
}

Performance of this solution is:

Runtime: 4 ms
Memory Usage: 2.2 MB