input: Write a function to find the largest three numbers in a list. If the list contains fewer than three numbers, return the largest numbers that are available. If the list is empty, return an empty list.
  assert find_largest_three([1, 6, 3, 8, 7, 4])==[6, 7, 8]
  assert find_largest_three([10, 20, 40])==[10, 20, 40]
  assert find_largest_three([5])==[5]
  assert find_largest_three([])==[]
output: def find_largest_three(nums):
      if not nums:
          return []
      nums.sort(reverse=True)
      return nums[:3]