* first we find the max element
max_element = 0
max_index = 0
for k = alen(arr) to 1 step -1
 if X >= arr(k)
   max_element = arr(k)
   max_index = k
 endif
endfor

*This solution is much easier if I was programming in c/c++ where I could
*use pointers.  We'll wing it tho ;) Really, what I want to do is have a 
*pointer to the max_element and one to the min_element, and then if their 
*sum is greater then x, I decrease the max_element, if their sum is less 
*then X I increase the min_element, if their sum equal X I end.  One final
*case, our end case, if max_element = min_element and max_ele + min_ele != 
*X, I return failure.

max_index = k
min_index = 1
do while arr(max_index)+arr(min_index) != X
  if arr(max_index)+arr(min_index) > X
    max_index = max_index - 1
  else if arr(max_index)+arr(min_index) < X
    min_index = min_index + 1
  else if arr(max_index) = arr(min_index)&&we already know their sum doesn't
                                         &&equal X, that's tested by our     
                                         &&our while loop
    return "Failure!"
  endif
enddo