CompSci 4 Test 2 Soln Spring 2009

1 A) When the world starts do
     While Shark distance to goldfish > 1 is true
     When not goldfish.isShowing becomes true

1 B) world.my first method
     shark turn to face goldfish
     shark move amount=0.25m toward target=goldfish
     shark.eat food=goldfish
     goldfish.reincarnate

1 C) When the world starts, the gold fish says hello and at the same time
the while event is true so the shark turns to face the goldfish and starts
moving it towards the goldfish until it is close to the goldfish. Then the
shark eats the goldfish and the goldfish disappears and reappears on the
other side of the seaweed. Then the while event kicks in and the shark
repeatedly goes to the goldfish and eats it and the goldfish then reappears
on the other side of the seaweed.

2. chicken, penguin stegosaurus, turtle, queenBee, lion

3. A) object
   B) parameter
   C) The function returns the first animal in the array that is more than
   twice the height of someObject. If there is no such object, then it
   returns  someObject.

4. A) 15
   B) 20
   C) 40
   D) She could have used a tool like Powerpoint or Paint to create the
   word Duke and import it in as a billboard, resizing it to that size.  Or
   she could have used 3-D text to create the word Duke.  In either case,
   she would have needed to glue it to the shirt with the vehicle property.

5. A. 4
   B. If the number is greater than 8, then there is no recursion.
   Notice the else always generates a larger number, so that eventually the
   number will be greater than 8 and the recursion will stop.
   C. 13
      10
      23

6. A) score.increment adds to the score, but does not display the new
value of the score. To do this you need to add the line:
   score set text to score.currentValue as a string

B)  score.increment 123 amount
    123 ranNum
    ranNum set value to random number min=1 max=amount+1 integerOnly=true
    score.currentValue set value to score.currentValue + ranNum
    score set text to score.currentValue as a string
    randomNumber set text to ranNum as a string

Add in a 3D text called randomNumber and set it's text to 0 initially.




7. Do Together
     horse turn to face princess    // Assume knight glued to the horse.
     dragon turn to face princess
   while knight distance to princess>1 and dragon distance to princess>1
      horse.gallop
      dragon.fly
   if knight distance to princess <=1
      princess say "Thanks for saving me!"
   else
      princess say "The Dragon has got me!"

8. A. In code below: IFP is item_from_penguins

obj world.GetColoredPenguin  123 distance  color selectedColor
For all world.penguins, one obj item_from_penguins at a time
    if IFP.color==selectedColor and lighthouse distance to IFP<distance
         return item_from_penguins
    else
         do nothing
return lighthouse

B. In the code below, 
GCP is world.GetColoredPenguin distance=range, selectedColor=desiredColor

world.takePenguins  123 range color desiredColor
   while   GCP != lighthouse
       lighthouse say "Got you"
       GCP move to lighthouse 
       GCP set vehicle to lighthouse
       GCP set color to no color
  lighthouse move up 100 meters

Alternative Soln:

world.takePenguins  123 range color desiredColor
   obj peng = GCP   // use object variable
   while   peng != lighthouse
       lighthouse say "Got you"
       peng move to lighthouse 
       peng set vehicle to lighthouse
       peng set color to no color
       peng = GCP
  lighthouse move up 100 meters
  
9. Note in code below AV is ArrayVisualization

A. 123 world.positionShorterThanIndex
      Loop 123 index from 0 up to but not including AV's size by 1
         if the value at AV[index]'s height < index
	    return index
	 else
	    do nothing
      return -1

B. world.resizeTilNoMore
   123 sum = 0
   while world.positionShorterThanIndex != -1
      the value at AV[world.positionShorterThanIndex] resize 2 more
      increment sum by 1
   print sum