Recursion assignment

Question

def swap(aList):

  if len(aList) == 0:
      return 0
  elif len(aList) == 1:
      print(aList[0])
      return aList[0]
  return aList[0] + swap(aList[2:])

aList = [         


        

Answer 1

Here's a pretty simple way

def swap (l):
  if len (l) < 2:
    return list (l)
  else:
    return [ l[1], l[0] ] + swap (l[2:])

print (swap ("abcdefgh"))
# ['b', 'a', 'd', 'c', 'f', 'e', 'h', 'g']

It works on arrays too

print (swap ([1, 2, 3, 4, 5, 6, 7]))
# [2, 1, 4, 3, 6, 5, 7]