Source code in the fortran programming language

PROGRAM TOWER
                             
  CALL Move(4, 1, 2, 3)
                
CONTAINS

  RECURSIVE SUBROUTINE Move(ndisks, from, to, via)
    INTEGER, INTENT (IN) :: ndisks, from, to, via
   
    IF (ndisks == 1) THEN
       WRITE(*, "(A,I1,A,I1)") "Move disk from pole ", from, " to pole ", to
    ELSE
       CALL Move(ndisks-1, from, via, to)
       CALL Move(1, from, to, via)
       CALL Move(ndisks-1, via, to, from)
    END IF
  END SUBROUTINE Move

END PROGRAM TOWER


PROGRAM TOWER2
 
  CALL Move(4, 1, 2, 3)
 
CONTAINS
 
  RECURSIVE SUBROUTINE Move(ndisks, from, via, to)
    INTEGER, INTENT (IN) :: ndisks, from, via, to
 
    IF (ndisks > 1) THEN
       CALL Move(ndisks-1, from, to, via)
       WRITE(*, "(A,I1,A,I1,A,I1)") "Move disk ", ndisks, "  from pole ", from, " to pole ", to
       Call Move(ndisks-1,via,from,to)
    ELSE
       WRITE(*, "(A,I1,A,I1,A,I1)") "Move disk ", ndisks, "  from pole ", from, " to pole ", to
    END IF
  END SUBROUTINE Move
 
END PROGRAM TOWER2