Last change
on this file since 3643 was
1910,
checked in by Laurent Fairhead, 11 years ago
|
Merged trunk changes r1860:1909 into testing branch
|
-
Property copyright set to
Name of program: LMDZ Creation date: 1984 Version: LMDZ5 License: CeCILL version 2 Holder: Laboratoire de m\'et\'eorologie dynamique, CNRS, UMR 8539 See the license file in the root directory
|
File size:
1.2 KB
|
Line | |
---|
1 | module get_divisors_m |
---|
2 | |
---|
3 | implicit none |
---|
4 | |
---|
5 | contains |
---|
6 | |
---|
7 | subroutine get_divisors(n, div) |
---|
8 | |
---|
9 | ! Find all the divisors of a given integer. |
---|
10 | |
---|
11 | integer, intent(in):: n |
---|
12 | integer, pointer:: div(:) |
---|
13 | |
---|
14 | ! Variables local to the procedure: |
---|
15 | |
---|
16 | integer i, i_max |
---|
17 | integer n_div ! number of divisors of "n" |
---|
18 | integer work(n) ! temporary array to hold divisors |
---|
19 | |
---|
20 | !------------------------ |
---|
21 | |
---|
22 | if (n <= 0) then |
---|
23 | print *, "get_divisors: n = ", n |
---|
24 | stop 1 |
---|
25 | end if |
---|
26 | |
---|
27 | if (n == 1) then |
---|
28 | work(1) = 1 |
---|
29 | n_div = 1 |
---|
30 | else |
---|
31 | ! n >= 2, there are at least two divisors: 1 and "n" |
---|
32 | work(1) = 1 |
---|
33 | work(2) = n |
---|
34 | n_div = 2 |
---|
35 | |
---|
36 | i_max = int(sqrt(real(n))) |
---|
37 | |
---|
38 | do i = 2, i_max - 1 |
---|
39 | if (mod(n, i) == 0) then |
---|
40 | work(n_div+1) = i |
---|
41 | work(n_div+2) = n / i |
---|
42 | n_div = n_div + 2 |
---|
43 | end if |
---|
44 | end do |
---|
45 | |
---|
46 | if (i_max >= 2 .and. mod(n, i_max) == 0) then |
---|
47 | work(n_div+1) = i_max |
---|
48 | n_div = n_div + 1 |
---|
49 | if (i_max**2 /= n) then |
---|
50 | work(n_div+1) = n / i_max |
---|
51 | n_div = n_div + 1 |
---|
52 | end if |
---|
53 | end if |
---|
54 | end if |
---|
55 | |
---|
56 | allocate(div(n_div)) |
---|
57 | div = work(:n_div) |
---|
58 | |
---|
59 | end subroutine get_divisors |
---|
60 | |
---|
61 | end module get_divisors_m |
---|
Note: See
TracBrowser
for help on using the repository browser.