Question

This is not something which I would do in real life, but say:

LinkedList = a,b,c,d,e and I get their corresponding index.

Say, I want to remove b (index=1) and d (index=3)(i.e. values surrounding c (index=j=2))

Now,I do (which works fine):

When j=2
LS.remove(j + 1); ----> j=3 (d removed)
LS.remove(j - 1); ----> j=1 (b removed)

And b and d are removed.

But if, I do (does not work):

When j=2
LS.remove(j - 1); ----> j=1 (b removed)
LS.remove(j); ----> j=2 (d is not removed) (used j because due to above removal, LL has adjusted it self)

i.e. when I move the value preceding ‘c’ first, ‘d’ is not removed and the LL stays as it is. I guess, I am doing the same thing.

Am I missing out on something here?

UPDATE:

So, when I change the signature public void operation(String operator, Integer j) to public void operation(String operator, int j), it worked.

Answer 1

If j is of type big Integer, then LinkedList.remove(Object) will be called instead of LinkedList.remove(int). And that’s not what you actually want.

I don’t see any reason to use big-Integer as the type of j in your second example, you should use primitive int.

Please check Why aren't Java Collections remove methods generic? on why LinkedList still has remove(Object) signature.