CompSci 4 Test 2 Fall 2010 Solutions

1. A) list events
When the world starts
When penguin distance to chair <= 1.5
When penguin distance to beachChair <=2.5
When the mouse clicks on an object

B) List event handlers
world.myFirstMethod
penguin.begin
penguin.sit
penguin say Goodbye
penguin.something
move the object clicked on

C) The penguin circles around the beachChair, says
"That was fun" and then moves 1 meter towards the chair. 
At this point he says "I'll sit", he turns to face the
chair and jumps up on it, then faces front. He then continuously
flaps his wings. 

D) The penguin says Goodbye, stops flapping his wings and then 
everything stated in C now happens again. 

2. cat    penguin    tortoise    joey    turtle    lemur

3. A) boolean
B) someColor is a parameter
C) total is a local variable
D) value is a parameter
E) mystery returns true if more than "value" animals 
have the color "someColor". Otherwise it returns false. 

F) yes

4. A) 3 times
   B) 12 times
   C) 18 times

5. A) Lines 5 and 7 have recursion
   B) The way out is if input < factor
   C) 3
      5
      2
      1

6. A)
   score.increase
   if item.color == red
      score.current set value to score.current + 3
   else
      score.current set value to score.current + 1
   score set text to score.current as a string
B)
  when (alienOnWheels distance to baseball < 0.25), 
     do score.increase item=baseball
  when (alienOnWheels distance to beachBall < 0.25), 
     do score.increase item=beachBall



7. 
123 world.numberInRange 123 min 123 max
123 total = 0
Loop 123 index from 0 up to but not including size of world.values incr by 1
   if both item index from world.values >= min and 
     item index from world.values <= max 
          total set value to total + 1
   else
     do nothing
Return total

8. A. 
world.randomlyColor color color
For all world.chickens, one obj item_from_Chickens at a time
   if choose true 50% of the time
      item_from_chickens set color to color
   else 
      item_from_chickens set color to white

8. A. ALT
world.randomlyColor color color
123 number = random  number min = 1 max = 3 integer only
For all world.chickens, one obj item_from_Chickens at a time
   if number == 1
      item_from_chickens set color to color
   else 
      item_from_chickens set color to white

B. 
123 world.ratioThisColor
123 count = 0
For all world.chickens one obj item_from_chickens at a time
   if item_from_chickens.color == color
      count set value to count + 1
   else
      do nothing
Return (count/size of world.chickens)

C. 
world.fixTheColoring color newColor
world.randomlyColor color=newColor
While world.ratioThisColor color=newColor <= 0.5
   world.randomlyColor color=newColor
print The percentage of blue chickens is joined with
   ((world.ratioThisColor color=newColor) as a string)

9A. 
123 world.lastOneShorter obj person
123 indexOfShorter = AV size - 1
Loop 123 index from 0 up to (bn including) AV's size incrementing by 1
   if the value at AV[index]'s height < person's height
      indexOfShorter set value to index
   else 
      do nothing
return indexOfShorter

9B.
world.Greetings obj visitor
Loop 123 index from 0 up to (bn including) AV's size incr by 1
   if index != world.lastOneShorter person = visitor
      the value at AV[index] say Hello
   else 
      the value at AV[index] say Boo Hoo, I am shorter than you