# Quiz #5 Solutions
# December 4, 2012

# Each problem was worth two points, except for #9, which was worth four points.

# 1. The following lines should be included:

if event.key == pygame.K_q:
    flag = False
    
# 2. There are a couple of solutions.  The most direct method is to type

if len(typed) == 21:   # >= 21 or > 20 both work too.
    flag = False
    
#  Notice that we used 21, since typed = ['z'] already has one character to begin with.
#  An alternate method is to include these lines at strategic spots

count = 0
...
count = count + 1
...
if count == 20:
    flag = False
    
# 3. Using this range ensures that letters stay on the screen, and not even
#  very close to the edge, when printed on the pygame window.

# 4. If we began with typed = [ ], the empty list, then when we first reached the line

if typed[-1] == typed[-2]:
    
#  there would be a run-time error, since there would only be one item in the list
#  at that point, so typed[-2] would be "out of range".

# 5. It keeps track of the x-coordinate of the left edge of the paddle.

# 6. In the line

if ballcount < 2:
    
# we should change the 2 to a 1.  (Or type if ballcount == 0:)

# 7. There are two methods for speeding up the game.  We could either
#  increase the speed of the balls by changing the code to assign
#  larger values to dx and dy at the start of the program, OR
#  we could increase the frame rate above 50 per second by typing

Clock.tick(80)

# Note that the latter results in smoother animation, so is preferable.

# 8. These are the lines that bounce the ball off the paddle.

# 9. There are five lines that need to be modified.  I awarded one point
#  per line, so only four changes need to be mentioned to receive full credit.

screen = pygame.display.set_mode([700,600])

    if px > 600:
        px = 600

        if balllist[j][0] > 690:
            balllist[j][0] = 1380 - balllist[j][0]