input: Write a function to implement the selection sort algorithm on a given list of integers. The function should return the sorted list in non-decreasing order. If the input list is empty, the function should return an empty list.
  
  assert sort_list([1, 5, 7, 8, 4, 10, 2])==[1, 2, 4, 5, 7, 8, 10]
  assert sort_list([10, 9, 8, 7, 6, 5, 4, 3, 2, 1])==[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
  assert sort_list([3, 3, 3, 3, 3])==[3, 3, 3, 3, 3]
  assert sort_list([])==[]
output: def sort_list(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