input: Write a function to print a staircase of height `n` where `n` is an integer. The staircase should be right-aligned, with each step consisting of a single `#` character. The width of the staircase should be equal to `n`. If `n` is 0, the function should print nothing.
  
  def staircase(n):
      for i in range(1, n + 1):
          print(" " * (n - i) + "#" * i)
  
  assert staircase(0) is None
  assert staircase(1) == "#"
  assert staircase(2) == " #\n##"
  assert staircase(3) == "  #\n ##\n###"
output: def staircase(n):
      for i in range(1, n + 1):
          print(" " * (n - i) + "#" * i)