Power of two?

Check if number is a power of 2

16 return true

15 return false

Solution: Bit wise comparison

public boolean powerOfTwo(int num){
    return ((num & (num - 1)) == 0 && num > 0);
}

num = 0b 0001 0000

num - 1 = 0b 0000 1111

num & num 1 == 0b 0000 0000

num not power2 = 0b 0001 0100

num - 1 = 0b 0001 0011

num not power2 & num - 1 == 0b 0001 0000