The Big Programming Thread - Page 763

On September 12 2016 13:05 Birdie wrote:
I haven't done much with userscripts before but pretty sure they have easy access to the DOM, so you just need to find how posts are stored in the DOM and then find the element with the username you want to hide, then remove it. IDK if that's enough to go off or you need more specifics though.

E.g.

<tr id="post-8073303">
					<td class="c_username">
					<a href='http://s9.zetaboards.com/Ultimate3D_community/profile/44616/' class='member'>AZARKON THE GREAT</a><a name='post8073303'></a>
					</td>

So you just navigate the DOM for anything with id = post-SOMETHING, then within its children, check class=member, check the text for the usernames you want to hide, and if so use whatever DOM manipulation userscripts have to hide/remove the whole post tr.

On September 14 2016 06:53 travis wrote:
let's saying im looping through an arraylist
checking for a certain result based on user input within it's elements

and when I am done, I want to change some of the indexes to something that I know *for sure* will not be what the user is searching for

is there a way to set indexes as "empty"? Is the only option to make those indexes null? meaning that I will have to account for that in my code? Or is there something easier than null.

Say, the indexes will have strings. Is there an option for a valueless string, or is null the best I can do?



(in java)


edit: epiphany. can I do "" ?

On September 14 2016 07:10 travis wrote:
sorry I didn't say what I mean accurately. I don't mean to change the index. I mean to change the value of the given index (the string) to something that the user wouldn't possibly be searching for.

I don't want to lose the index itself, or else I would just remove it from my arraylist.

if (arrList.contains("search string")) {
    arrList.set(arrList.indexOf("search string"), "won't find it again!");
}
   /*
    can just set it to null if you want to, but this might break things since both
    contains and indexOf need an object of some sort as their argument
   */

On September 12 2016 13:25 WarSame wrote:

I mean, I'm not particularly good, but couldn't you just put the pointer values of each node in a dict when visited, and if you come to a node already in the dict, then you've got a loop?

On September 14 2016 11:15 Blisse wrote:
Why can't you just remove the objects from the list if you know you don't need them?



How would you approach the problem if you couldn't hash the objects because the list is huge?

+ Show Spoiler [hint] +

On September 14 2016 06:53 travis wrote:
let's saying im looping through an arraylist
checking for a certain result based on user input within it's elements

and when I am done, I want to change some of the indexes to something that I know *for sure* will not be what the user is searching for

is there a way to set indexes as "empty"? Is the only option to make those indexes null? meaning that I will have to account for that in my code? Or is there something easier than null.

Say, the indexes will have strings. Is there an option for a valueless string, or is null the best I can do?



(in java)


edit: epiphany. can I do "" ?

On September 14 2016 17:34 Morfildur wrote:



Pointers are tiny, so even a list with a million entries will have pretty much insignificant memory impact compared to the list and data itself, so a simple dictionary solution would still be pretty easy and probably faster, too, since you can abort on the first duplicate node. With the tortoise and hare solution you have to cross the distance that the slower pointer completed already, which means in a completely circular list you pretty much have to check 1.5n elements. The slower pointer crosses half the distance in the time for one complete loop, so now the faster pointer has to move around again until it reaches the slower pointer which is half the loop ahead. You can increase the speed at which the faster pointer moves, but then you'll be slower for partial loops that the faster pointer will circle around multiple times before the slower even enters them.

In any case, the situation is completely academic since you should never have to check in code whether a list is circular or not. You should never actually interact with the nodes directly, only the data they contain, which means that you couldn't even be able to create any loops in a non-circular list if you wanted to. If you create your own linked list implementation then your code shouldn't allow for the possibility of a loop when you don't want one and making such a potentially expensive check at runtime inside a library is generally a bad idea.

On September 14 2016 16:41 Aerisky wrote:
afaik it's not too obscure, so people might have heard of it. I think I remember seeing it in a small lab assignment in my lower data structures/algorithms class a couple years ago.

On September 14 2016 17:34 Morfildur wrote:
In any case, the situation is completely academic since you should never have to check in code whether a list is circular or not. You should never actually interact with the nodes directly, only the data they contain, which means that you couldn't even be able to create any loops in a non-circular list if you wanted to. If you create your own linked list implementation then your code shouldn't allow for the possibility of a loop when you don't want one and making such a potentially expensive check at runtime inside a library is generally a bad idea.

On September 14 2016 07:40 travis wrote:
there will be multiple search terms, and I don't know what they are, so I can't set it to another string

I know I can set it to null, I was just wondering if there was a better option - is empty string a thing?