Do my runtime make sense?

Question

HI..me again
I just finished my code for runtime. And i am getting the runtime of the ArrayList implementation lower then the LinkedList Implementation. Does that make sense?
Shouldnt the ArrayList runtime be higher ? at least thats what I am told by all my friends
Note*= my assingnment was to create an Array and a linked list implementation of an unordered set. The interface had the following methods:
public interface MySet {
    boolean isIn(Value v);
    void add(Value v);
    void remove(Value v);
    MySet union(MySet s);
    MySet intersect(MySet s);
    MySet difference(MySet s);
    int size();
    void printSet();
}thanks for any reply:)
Note*:new to programming
Edited by: haraminoI on Mar 28, 2009 10:10 AM
Edited by: haraminoI on Mar 28, 2009 10:12 AM
Edited by: haraminoI on Mar 28, 2009 10:12 AM
Edited by: haraminoI on Mar 28, 2009 10:13 AM
Edited by: haraminoI on Mar 28, 2009 10:20 AM

Answer 1

Which methods run faster for ArrayList?
Which methods run faster for LinkedList?
How large are the sets that you are using to do your tests? A larger set will show the differences better than a smaller set will.
Try adding 1000 numbers to each set (add 1, 2, 3, ...,1000, in order). Which set could add them faster? [If it one isn't particularly faster or slower, try 10000 numbers or 50000 numbers.]
Then try to remove the number '1' from each set. Which set could remove it faster?
Then try to remove '500' from each set. Which set could remove it faster?
Then try to remove '1000' [or other end number] from each set. Which set could remove it faster?
Try calculating "size()" for each set. Which set gives you the answer faster (assuming you haven't kept a 'size' variable in your LinkedList, and that you calculate the size() by iterating through the list)?
If you want to test with random numbers, you should add the same numbers to both lists in the same order. You might also want to keep track of what number is first, some numbers known to be in the middle, and some numbers at the end, so you can test how fast removal of the first element is. The "set" may be unordered, but the list will still be holding the items in the order that you added them.
You should see that some operations are faster using ArrayList, and some are faster using LinkedList. Your exact implementations may cause some difference, but if the implementations are reasonable, there are certain operations that should be faster with ArrayList and certain that should be faster with LinkedList.