HINTS for Lab 6
---------------

1. It will be useful to write the following two functions:

def moveCell(pic1,cell1,pic2,cell2):
# pic1 and pic2 are the two picture objects and 
# cell1 and cell2 are numbers in the range 1..6
# the function moves the image located in cell1
# of pic1 to location cell2 of pic2

def exchangeCell(pic1,cell1,pic2,cell2):
# pic1 and pic2 are the two picture objects and 
# cell1 and cell2 are numbers in the range 1..6
# the function exchanges the images located in cell1
# of pic1 and cell2 of pic2

2. Note that the top-left corner of the images in the cells
are located at the following coordinates:

cell   top-left corner 
       coordinates 
---------------------------------
1	(0,0)             
2	(240,0)
3	(480,0)
4	(0,240)
5	(240,240)
6	(480,240)

Also note the following relationships between cell number and
top-left corner coordinate:

x = 240*((cell-1)%3)
y = 240*((cell-1)/3)

3. To randomly scramble the sub-images, you may use the following
technique:

set up a list
  occupied = [False, False, False, False, False, False]
which indicates that initially all six cells are unoccupied.
Then,
for each sub-image:
  repeatedly generate a random cell number between 1 and 6
  until you find that the cell is unoccupied.
  Move the next sub-image to this cell.
  set the occupied entry for this cell to True