Array pair element doubt

#1

hi,
is it possible to find all pair of elements in array in linear time?
like if we have 1,2,3,4., I want
(1 2) (1 3) (1 4) (2 3) (2 4) (3 4) O(n) time.
Thanks

#2

Since you want to print all pairs it is not possible in O(n).