CompSci 94 Exam 2 Fall 2019 Solutions

Problem 1
PART A. (4 pts)
The bunny moves forward 1.0 (and collides with the hare).
Then the hare moves backward 1.0.
Then the bunny moves forward 1.0 (and collides with the pig).
Then the pig moves backward 1.0.
Then the bunny says "hello".

Problem 1
PART B - A) (3 pts)
The hare moves left 3.0 (actually moves left 1.0 three times)
Then the pig moves backward 1.0

Note: The hare also collides with the bunny but there is no collision event
for that.

Problem 1
PART B - B) (3 pts)
The user presses the B key and the bunny moves forward 1.0.
The user presses the B key two more times and the bunny collides with the
panda. The panda will move backward 1.0.
Then everytime the user presses the B key the bunny moves forward 1 and
collides with the panda, who moves backward 1.


Problem 2
Part A (6 pts)
The animals one at a time move up 1 in the order they are shown from left
to right, marchHare first, then whiteRabbit, etc.
Then the animals all together move down 1.0.
Then the marchHare says hello, then the tortoise says hello and then the
bunny says hello.

Problem 2
Part B (4 pts)
The first three animals in the array are painted blue. That is, the
marchHare, whiteRabbit and tortoise, one at a time are painted blue.

Problem 2
Part C (4 pts)
The whiteRabbit is painted Gray.
Then Alice is painted red
Then the panda is painted green.


Problem 3 PART A (9 pts)
A) variable
B) total length of pandas in the array
C) 10
D) The mysteryProc processes all the pandas in the pandas array. If a panda
is red it is doubled in size, and otherwise the panda resizes to half its
size.


Problem 3 PART B (7 pts)
A) wholeNumber
B) mysteryFunction returns the number of pandas that are shorter than
someAnimal.
C) mysteryFunction now returns the total number of pandas plus the number
of pandas that are shorter than someAnimal. 

Problem 4 (8 pts)
A) cow says hello and moves up and down
B) wolf says hello and moves backwards
C) poodle says hello and turns once around
D) nothing

Problem 5 (12 pts)
A) Allows you to click on any object and drag it around in the scene.
B) Bunny says "CompSci 94" and then the penguin says "score".
C) Flamingo turns around once and the panda says "The end"
D) nothing happens, they are both in set A.
E)

addCollisionStartListener new SThing[] {flamingo}, new SThing[] {bunny,
pentuin, panda}
declare procedure collisionStarted event getSThingFromSetA, event getSthingFromSetB
getsthingFromSetB setOpacity opacity 0.0


Problem 6 (12 pts)

A) Tortoise says Click on Tortoises for points, then the timer is set to 20
and the score is set to 0.

B) Add a wholeNumber  parameter named amount.

Then the first line should be changed to:
this.setTimerNumber timerNumber this.timerNumber - amount

C) this.timer updateTimer amount 1

D) addMouseClickOnObjectListener setOfVisuals this.yetibabies

this.timer updateTimer amount -5

E) In the timeElapsed event the code should be:

if timerNumber > 0 then
   this.timer updateTimer amount 1


Problem 7 (6 pts)

A) All the bunnies move down 10 when the wolf collides with a single
bunny. Only that bunny is supposed to move down. The score should increase
by the correct amount.

B) The line "someBunny move Down 10" should be the first line in the first
if statement. That is the code should be:

for each Bunny someBunny in this.bunnies
   if someBunny == event.getSthingFromSetB is true then
         someBunny move Down 10.0 duration 0.0
	 if someBunny getPaint == RED is true then
	      this.Scorer increaseScore amount 3
         else
	      this.Scorer increaseScore amount 1
    else
         Do nothing
loop ends


Problem 8
Part A) (6 pts)
declare procedure resizeSmallOnes DecimalNumber heightCutOff,
        DecimalNumber minNumber, DecimalNumber maxNumber

for each Bunny someBunny in this.bunnies
    if someBunny getHeight < heightCutoff
        someBunny resize nextRandomRealNumberInRange minNumber maxNumber


Problem 8
Part B) (6 pts)
declare procedure changeColor WholeNumber amount, Paint someColor

WholeNumber index = 0
count up to amount
   bunnies[index] setPaint paint someColor
   index <-- index + 1


ALT SOLN:

declare procedure changeColor WholeNumber amount, Paint someColor

WholeNumber index = 0
while index < amount is true
   bunnies[index] setPaint paint someColor
   index <-- index + 1


Problem 8
Part C) (6 pts)

declare WholeNumber function howManyTheseColors Paint color1, Paint color2

WholeNumber count = 0
for each Bunny oneBunny in this.bunnies
   if oneBunny getPaint == color1 OR if oneBunny getPaint == color2 then
      count <- count + 1
return count


ALT SOLN:

declare WholeNumber function howManyTheseColors Paint color1, Paint color2

WholeNumber count = 0
for each Bunny oneBunny in this.bunnies
   if oneBunny getPaint == color1 then
      count <- count + 1
   else
      if oneBunny getPaint == color2 then
          count <- count + 1
return count

ALT SOLN

WholeNumber count = 0   // this variable is for counting
WholeNumber index = 0   // this variable is for indexing the array
while index < bunnies.length
   if bunnies[index] getPaint == color1 OR if bunnies[index] getPaint == color2 then
      count <- count + 1
   index <- index + 1   
return count

Note: index gets updated each time in the loop, whereas count only gets
updated if the color of the bunny matches.