Power of Two

Problem

Return True if the integer n is a power of two and False otherwise, including for n <= 0.

A positive power of two has exactly one set bit, so the expression n & (n - 1) equals zero. Do not use logarithms or loops.

Hint

Subtracting 1 flips the single set bit and all lower bits, so the AND clears everything.

case 1

in: [1]

expected: true

case 2

in: [16]

expected: true

case 3

in: [3]

expected: false

case 4

in: [0]

expected: false

case 5

in: [-4]

expected: false

Starter codePython

def is_power_of_two(n):
    # Your code here
    pass

5 test cases · run your code against them in the editor