input: Write a function to generate an array of specified length with random numbers ranging from 1 to 100. If the given length is 0, return an empty array.
  assert populateArray(5)==[30, 15, 78, 22, 99]
  assert populateArray(0)==[]
  assert populateArray(3)==[45, 88, 12]
output: import random
  
  def populateArray(length):
      if length == 0:
          return []
      return [random.randint(1, 100) for _ in range(length)]