Lecture Notes on 25 July 2014

def substr (st):
  wnd = len (st)
  while (wnd > 0):
    index = 0
    while ((index + wnd) <= len(st)):
      print (st[index:index + wnd])
      index = index + 1
    wnd = wnd - 1

def main ():
  substr ('ABCD')

main()