input: Write a function to check if a string `s` has matching parentheses. If it does, return True; otherwise, return False.
  assert matching_paren("( )")==True
  assert matching_paren("((())))")==False
  assert matching_paren("(()))")==False
  assert matching_paren("((()))")==True
  assert matching_paren("")==True
output: def matching_paren(s):
      count = 0
      for char in s:
          if char == '(':
              count += 1
          elif char == ')':
              count -= 1
          if count < 0:
              return False
      return count == 0