its a greedy+dp according to me

you should analyze the four scenario like

1. two increasing sequence :

     take two array . two array initially have only one value zero. then iterate over 2nd to nth element.

     if element > 1st and 2nd arrays last element
             then, 1st sequence last element > 2nd arrays last element then: (add element
                                                                  to the 1st array)
             otherwise (add element to the 1st array)
     otherwise   add it to the array whose last element < element

     (this is optimal ).

2. two decreasing sequence: approach greedily like 1st one

3. one increasing and one decreasing(1st element included in the increasing array):(try yourself)

4. one increasing and one decreasing(1st element included in the decreasing array):(try yourself)

for 3rd and 4th criteria , think greedily also.

my solution is 0.14sec
if you are better plz email me s-2017915104@isrt.du.ac.bd