Questions on HW5-Summer07

Questions on HW5-Summer07

Ask Questions on homework 5 here. Please enclose code with <code> </code> tags.

Question: Maybe I missed something, but I'm not sure how you get an index from a linked list (though I know how to do it for an array), and I don't know how to get the total length of the linked list (unless you use a count method from LLNode or treat it as a stack and get the size). Any leads?

There is no way to get the index out of the linked list (with the provided code anyway), but the amount you need to move to the list (int index) is already provided as a parameter why do you need to be able to index a linked list at all? Use our good friend the for loop. Dawn Finney.

Comment: Hahahaha this took me sometime to figure out. When I was adding the elements in the list it would add once but if I tried to do it twice it wouldn't do it. Apparently I was trying to foolishly add 'addElement' to the list and on successive loops it would try to add 'addElement' to itself, which ofcourse means that at the end the next attribute of 'addElement' would only be pointing to some other unique element in the list and 'addElement' was added only once.

If anyone else had this problem, the solution is to make a new temporary node inside the loop and pass the picture of the 'addElement' as the argument of the constructor.
The actual solution is to use .copy() to create a copy of addElement, which is basically what you finally did. I mentioned that you need to "add the amount of copies of addElement as specified by numOfCopies" in the homework 5 description. Notice how I explicitly said "copies." Even the name of the variable numOfCopies gives it away. I also put inside the recitation for Monday and Wednesday of last week descriptions of good methods to use for the homework including .copy(). I'm just basically saying that I feed you hints the whole way. You just have to pay attention. Dawn Finney

Question: Perhaps I'm not paying attention, but I don't understand how the parameters are to be passed to the methods that we test in PictureTest. Do we specify the parameters through the Interaction Panel (and do we have to prompt the user for the input)? Do we place them as initialized values in the body of PictureTest? I'm assuming they are not read from an I/O file since we haven't touched on that. (But then we haven't touched on prompting the user for input, either.) Sorry if I missed hints fed to me...

You test your methods in PictureTest with hardcoded parameters. This part of the assignment is to simulate what you would do real life if you were to write a method for someone else to use. You would test your methods extensively to make sure it works according to the specifications. The minimum requirement for the homework is to test each method once with hardcoded parameters. Yeah we definitely did not touch on the I/O stuff yet. Dawn Finney.

Question: What is the best way to assign a random number to each node?

You don't really have to assign a random number per say. Traverse the list and for each node generate a random number to decide what to do with the Picture inside the node.

Question: In the doARandomPictureManipulation(), is each NODE supposed to have a different manipulation or just each different picture. Any pictures that are the same in mine always turn out with the same manipulation and I don't know how to fix that (if it needs to be fixed).

Well technically each node is supposed to have a different manipulation, but some of the node may contain the same exact Picture so it's possible that two nodes have the same Picture with the same manipulation. We're not taking off points for this. Dawn Finney.

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Homeworks-Summer 2007 last edited on 21 July 2007 at 10:06 am by adsl-154-122-133.asm.bellsouth.net