input: Write a function to print a staircase of height 'n', where n is an integer. Each step of the staircase should be represented by the character '#', and the steps should be right-aligned. If n is 0, the function should print an empty line.
  
  assert staircase(5) == None
  assert staircase(3) == None
  assert staircase(0) == None
  assert staircase(7) == None
  assert staircase(1) == None
output: def staircase(n):
      for i in range(1, n + 1):
          print(' ' * (n - i) + '#' * i)