RosettaCodeData/Task/Anagrams/Fantom/anagrams-2.fantom
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2013-04-10 21:29:02 -07:00

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!***************************************************************************************
module anagram_routines
!***************************************************************************************
implicit none
!the dictionary file:
integer,parameter :: file_unit = 1000
character(len=*),parameter :: filename = 'unixdict.txt'
!maximum number of characters in a word:
integer,parameter :: max_chars = 50
!maximum number of characters in the string displaying the anagram lists:
integer,parameter :: str_len = 256
type word
character(len=max_chars) :: str = repeat(' ',max_chars) !the word from the dictionary
integer :: n = 0 !length of this word
integer :: n_anagrams = 0 !number of anagrams found
logical :: checked = .false. !if this one has already been checked
character(len=str_len) :: anagrams = repeat(' ',str_len) !the anagram list for this word
end type word
!the dictionary structure:
type(word),dimension(:),allocatable,target :: dict
contains
!***************************************************************************************
!******************************************************************************
function count_lines_in_file(fid) result(n_lines)
!******************************************************************************
implicit none
integer :: n_lines
integer,intent(in) :: fid
character(len=1) :: tmp
integer :: i
integer :: ios
!the file is assumed to be open already.
rewind(fid) !rewind to beginning of the file
n_lines = 0
do !read each line until the end of the file.
read(fid,'(A1)',iostat=ios) tmp
if (ios < 0) exit !End of file
n_lines = n_lines + 1 !row counter
end do
rewind(fid) !rewind to beginning of the file
!******************************************************************************
end function count_lines_in_file
!******************************************************************************
!******************************************************************************
pure elemental function is_anagram(x,y)
!******************************************************************************
implicit none
character(len=*),intent(in) :: x
character(len=*),intent(in) :: y
logical :: is_anagram
character(len=len(x)) :: x_tmp !a copy of x
integer :: i,j
!a character not found in any word:
character(len=1),parameter :: null = achar(0)
!x and y are assumed to be the same size.
x_tmp = x
do i=1,len_trim(x)
j = index(x_tmp, y(i:i)) !look for this character in x_tmp
if (j/=0) then
x_tmp(j:j) = null !clear it so it won't be checked again
else
is_anagram = .false. !character not found: x,y are not anagrams
return
end if
end do
!if we got to this point, all the characters
! were the same, so x,y are anagrams:
is_anagram = .true.
!******************************************************************************
end function is_anagram
!******************************************************************************
!***************************************************************************************
end module anagram_routines
!***************************************************************************************
!***************************************************************************************
program main
!***************************************************************************************
use anagram_routines
implicit none
integer :: n,i,j,n_max
type(word),pointer :: x,y
logical :: first_word
real :: start, finish
call cpu_time(start) !..start timer
!open the dictionary and read in all the words:
open(unit=file_unit,file=filename) !open the file
n = count_lines_in_file(file_unit) !count lines in the file
allocate(dict(n)) !allocate dictionary structure
do i=1,n !
read(file_unit,'(A)') dict(i)%str !each line is a word in the dictionary
dict(i)%n = len_trim(dict(i)%str) !saving length here to avoid trim's below
end do
close(file_unit) !close the file
!search dictionary for anagrams:
do i=1,n
x => dict(i) !pointer to simplify code
first_word = .true. !initialize
do j=i,n
y => dict(j) !pointer to simplify code
!checks to avoid checking words unnecessarily:
if (x%checked .or. y%checked) cycle !both must not have been checked already
if (x%n/=y%n) cycle !must be the same size
if (x%str(1:x%n)==y%str(1:y%n)) cycle !can't be the same word
! check to see if x,y are anagrams:
if (is_anagram(x%str(1:x%n), y%str(1:y%n))) then
!they are anagrams.
y%checked = .true. !don't check this one again.
x%n_anagrams = x%n_anagrams + 1
if (first_word) then
!this is the first anagram found for this word.
first_word = .false.
x%n_anagrams = x%n_anagrams + 1
x%anagrams = trim(x%anagrams)//x%str(1:x%n) !add first word to list
end if
x%anagrams = trim(x%anagrams)//','//y%str(1:y%n) !add next word to list
end if
end do
x%checked = .true. !don't check this one again
end do
!anagram groups with the most words:
write(*,*) ''
n_max = maxval(dict%n_anagrams)
do i=1,n
if (dict(i)%n_anagrams==n_max) write(*,'(A)') trim(dict(i)%anagrams)
end do
!anagram group containing longest words:
write(*,*) ''
n_max = maxval(dict%n, mask=dict%n_anagrams>0)
do i=1,n
if (dict(i)%n_anagrams>0 .and. dict(i)%n==n_max) write(*,'(A)') trim(dict(i)%anagrams)
end do
write(*,*) ''
call cpu_time(finish) !...stop timer
write(*,'(A,F6.3,A)') '[Runtime = ',finish-start,' sec]'
write(*,*) ''
!***************************************************************************************
end program main
!***************************************************************************************