power-of-2 created by barbchoy - https://repl.it/Br7W/2659

power-of-2.rb

# Write a method that takes in a number and returns true if it is a
# power of 2. Otherwise, return false.
#
# You may want to use the `%` modulo operation. `5 % 2` returns the
# remainder when dividing 5 by 2; therefore, `5 % 2 == 1`. In the case
# of `6 % 2`, since 2 evenly divides 6 with no remainder, `6 % 2 == 0`.
#
# Difficulty: medium.

def is_power_of_two?(num)
  result = false
  while num%2==0 && num!=0
  num=num/2
  result =true
end
if num%2!=0
  result = false
end
if num==1
  result=true
end
return result
end

# These are tests to check that your code is working. After writing
# your solution, they should all print true.

puts("\nTests for #is_power_of_two?")
puts("===============================================")
    puts('is_power_of_two?(1) == true: ' + (is_power_of_two?(1) == true).to_s)
    puts('is_power_of_two?(16) == true: ' + (is_power_of_two?(16) == true).to_s)
    puts('is_power_of_two?(64) == true: ' + (is_power_of_two?(64) == true).to_s)
    puts('is_power_of_two?(78) == false: ' + (is_power_of_two?(78) == false).to_s)
    puts('is_power_of_two?(0) == false: ' + (is_power_of_two?(0) == false).to_s)
puts("===============================================")