Select from a list of numbers out of order the ones that aren't correlative

Questions
1

I try with a list like this one

{2, 8, 9, 6, 3, 3, 9, 2, 4, 6, 10, 2, 1, 0, 3, 9, 3, 9, 7, 10}

and pretend to Select elements that are not like 8,9 or 9,8 or 3,3
I tried using as condition Abs[#1 - #2]>1 but gives a mistake slot out off range … I suppose I need to focus the solution otherwise.
Thanks for ideas

2

As your problem is not strictly formulated, I can only suppose that the following code may be appropriate to your aim.

In[1]:= list = {2, 8, 9, 6, 3, 3, 9, 2, 4, 6, 10, 2, 1, 0, 3, 9, 3, 9,
    7, 10};

list //. {a___, b_, c_, d___} /; Abs[b - c] <= 1 -> {a, d}

Out[2]= {2, 6, 9, 2, 4, 6, 10, 0, 3, 9, 3, 9, 7, 10}
3

Really good solution, I would say fast and clean !!
At the moment I stay working a long and not clean solution going on subsequences of two elements and then
Select[ mlist, Abs[#[[1]] - #[[2]]] > 1 &] that works but slowly
Sincerely THANKS

4

It is my pleasure!