Adding visualise for skiplist

[aveldan]

Added visualise for skiplist. #64 This is how it looks for one example

[spirosmaggioros]

Thanks once again for the implementation! Can you remove the zeros at the front? I can't understand the need to have these nodes there.Everything else seems pretty good to me.

[aveldan]

Do you mean the nodes with value 0. I think in the example I created I insert 0 as a key value, those 0s are those values. Or do you mean to remove nodes with root or NULL

[spirosmaggioros]

I run this example:

skip_list<int> s(2, 0.3);
  s.insert(1);
  s.insert(4);
  s.insert(13);
  s.insert(5);
  s.insert(6);
  std::cout << s << '\n';
  s.visualize();

and the result was this:

But 0 does not exist in the elements

[aveldan]

let me check

[spirosmaggioros]

For me it's still there. No? If im wrong please let me know, i just checked.

[aveldan]

This is what I get from example you gave

skip_list<int> s(2, 0.3);
  s.insert(1);
  s.insert(4);
  s.insert(13);
  s.insert(5);
  s.insert(6);
  std::cout << s << '\n';
  s.visualize();

I think you might have not updated your code.

The problem I found was that our skip_list's root had key = 0 in it and I was creating nodes for that and also an extra node called root. Instead I took care of it by just going to next head = head->next[i] whenever head is root. That should resolve it. I have tried a few other examples also they don't seem to create nodes with 0.

The above one was for this

skip_list<int> s(3, 0.5);
  s.insert(3);
  s.insert(6);
  s.insert(7);
  s.insert(9);
  s.insert(12);
  s.insert(19);
  s.insert(17);
  s.insert(15);
  s.insert(100);
  s.insert(500);
  s.insert(174);
  s.insert(1234);

[spirosmaggioros]

Yes it is fixed, sorry for this i forgot to fetch your PR and i did not have the updates. PR will be merged