tasks a-s

Task/Reverse-a-string/Fortran/reverse-a-string-1.f

@@ -0,0 +1,16 @@
+PROGRAM Example
+
+  CHARACTER(80) :: str = "This is a string"
+  CHARACTER :: temp
+  INTEGER :: i, length
+
+  WRITE (*,*) str
+  length = LEN_TRIM(str) ! Ignores trailing blanks. Use LEN(str) to reverse those as well
+  DO i = 1, length/2
+     temp = str(i:i)
+     str(i:i) = str(length+1-i:length+1-i)
+     str(length+1-i:length+1-i) = temp
+  END DO
+  WRITE(*,*) str
+
+END PROGRAM Example

Task/Reverse-a-string/Fortran/reverse-a-string-2.f

@@ -0,0 +1,25 @@
+program reverse_string
+
+  implicit none
+  character (*), parameter :: string = 'no devil lived on'
+
+  write (*, '(a)') string
+  write (*, '(a)') reverse (string)
+
+contains
+
+  recursive function reverse (string) result (res)
+
+    implicit none
+    character (*), intent (in) :: string
+    character (len (string)) :: res
+
+    if (len (string) == 0) then
+      res = ''
+    else
+      res = string (len (string) :) // reverse (string (: len (string) - 1))
+    end if
+
+  end function reverse
+
+end program reverse_string