Check for runner ups

Sliding_max_tutorial

#check if what's currently in the back is a potential winner
if deque.topBack > array[i] 
    #if it is, store the runner up behind it
    deque.pushBack(array[i])
else
    #if it's not, remove it and then store the new winner in the back
    deque.popBack
    deque.pushBack(array[i])
end