AP Computer Science A 2018 Free Response Discussion

In this video, we discuss the AP Computer Science A 2018 Free Response questions. We go over each FRQ and discuss what an optimal answer would look like.

[michaelsteinberg]

Hold up isn't arr2D.size() supposed to be arr2D.length? Its a 2D array not an arraylist.

[PhoenixBlaze]

I have the Compsci Test Tomorrow and the free response have been the difference from a 4 and a 5 - This is gold for me right now

[palashchavan]

Life saver thanks for the effort exam in 2 days!!! Fingers crossed

[anish.seeniraj]

An insightful discussion as always!
But it looks like the region I'm in received a set of completely different questions

[Mcdude]

Like 4 hours until my test this is gonna be the worst :(

[lilrey]

In 1B in the for loop, would you need to write run <= num because you wanna run as many times as num or no?

[during]

For the fourth frq does it matter if the question was started by checking the column for duplicates and then going through the 2D array?

[palashchavan]

For number 3, could you write return( the whole left column with and between them then greater than zero)??

[pulaktaneja]

For 1(b), aren't we supposed to use a FrogSimulation array, which we then traverse and check the individual objects with the simulate method?

[jayantirakshit]

hi!! i have a question about part 4b. so when you were setting up your 2nd and 3rd if statements about whether or not the first row equals the other rows/columns, why did you use the || instead of &&? shouldn't we use && because if a it passes both parameters, then it'd return false??

[lll]

*at **20:15** shouldn’t it be: if(str.length() < lo) ... instead of: if(str.length <lo) ... because you’re finding the length of a string not an array?*

[shardstealth]

In part b of question 4 would you need to have containsduplicates() in your for loops? Since you are comparing it to an array that doesn't have duplicates then to have all of that original rows numbers the row must not have any duplicates itself.

[during]

How much of a deduction would not initializing the allpairs arraylist in question 2A be ?

[helendong]

for the third question can you do .contains instead of .indexOf?

[beddy]

for 1(b) would run <= num be wrong for the for loop since u want to include every single one of the parameter?

[ethanpang]

For 4b, when calling that static methods getColumn, hasAllValues and containsDuplicates, they grade it the same whether or not you call the method using the class name right? Ex: "containsDuplicates()" would be graded the same as

[shalphan]

For 2A, if I made the outer for loop end at (words.length-1), would it change the result (because you need i+1 to be less than words.length)

EDIT: *2A, my bad

[youtubeaccountx]

29:20 you can’t just make square a one dimensional array?? How does that work???

[AlanZhaobadmintonplayer]

How many points would be deducted for not initializing the updated variable in the for loop (i.e., writing for (i = 0...) instead of for (int i = 0...))?

[sundharvs]

How may points do you think will be deducted if I didn't return false if position <0 for part a of question 1?