input: Write a function to sort a list of integers in ascending order by implementing the selection sort algorithm. The function should take a list of integers as input and return the sorted list. If the input list is empty, the function should return an empty list.
  assert sort_ascending([3, 4, 5, 1, 2])==[1, 2, 3, 4, 5]
  assert sort_ascending([3, 5, 10, 1, 2])==[1, 2, 3, 5, 10]
  assert sort_ascending([4, 3, 1, 2])==[1, 2, 3, 4]
  assert sort_ascending([3, 5, 4, 1, 2])==[1, 2, 3, 4, 5]
  assert sort_ascending([])==[]
output: def sort_ascending(lst):
      if not lst:
          return []
      for i in range(len(lst)):
          min_idx = i
          for j in range(i+1, len(lst)):
              if lst[j] < lst[min_idx]:
                  min_idx = j
          lst[i], lst[min_idx] = lst[min_idx], lst[i]
      return lst