Daily programmer #63 easy: Reverse an Array

daily63e.f03

! File: daily63e.f08
! Programmer: Cameron Carroll
! Created June 2012
! Last Modified June 13, 2012

! Purpose: Implement a function that takes an integer and an array,
!    and reverses the first (integer) items of that array.
!
! For Reddit DailyProgrammer 63 Easy
! http://www.reddit.com/r/dailyprogrammer/comments/uw14f/6112012_challenge_63_easy/



module Daily63e
	implicit none

contains
	function reverseN(n, array, numel)
		integer, intent(in) :: numel, array(numel), n
		integer	:: itemCounterUp, itemCounterDown, activePortion(n), &
																				& reverseN(numel), remainder(numel - n)

		itemCounterDown = n
		itemCounterUp = 1

		do while (itemCounterDown /= 0)
			activePortion(itemCounterUp) = array(itemCounterDown)
			itemCounterDown = itemCounterDown - 1
			itemCounterUp = itemCounterUp + 1
		end do

		remainder = array(n+1:numel)
		reverseN(1:size(activePortion)) = activePortion
		reverseN(size(activePortion)+1:size(activePortion)+size(remainder)) = remainder

	end function reverseN


end module Daily63e

!-------------------------------------------------------------------!
! Driver                                                            !
!-------------------------------------------------------------------!
program main

	use Daily63e
	implicit none

	integer :: ary(5), newary(5)
	integer :: ary2(10), newary2(10)

	ary = [1, 2, 3, 4, 5]
	newary = reverseN(3, ary, size(ary))
	print*, newary

	ary2 = [950, 485, 2734, 5749, 54473, 49430, 4837, 439430, 438438, 2710]
	newary2 = reverseN(8, ary2, size(ary2))
	print*, newary2

	


end program main