program sort
        real, dimension(4)::a
        a(2)=3
        a(1)=9
        a(3)=8
        a(4)=5 

        call bubble_sort(a)

        print*,a
        stop
        end
        
        SUBROUTINE Bubble_Sort(a)
        REAL, INTENT(in out), DIMENSION(:) :: a
        REAL :: temp
        INTEGER :: i, j
        LOGICAL :: swapped = .TRUE.
 
        DO j = SIZE(a)-1, 1, -1
          swapped = .FALSE.
          DO i = 1, j
            IF (a(i) > a(i+1)) THEN
              temp = a(i)
              a(i) = a(i+1)
              a(i+1) = temp
              swapped = .TRUE.
            END IF
          END DO
          IF (.NOT. swapped) EXIT
        END DO
      END SUBROUTINE Bubble_Sort