Data update

Task/Permutations/Ada/permutations-1.ada

@@ -1,9 +0,0 @@
-generic
-   N: positive;
-package Generic_Perm is
-   subtype Element is Positive range 1 .. N;
-   type Permutation is array(Element) of Element;
-
-   procedure Set_To_First(P: out Permutation; Is_Last: out Boolean);
-   procedure Go_To_Next(P: in out Permutation; Is_Last: out Boolean);
-end Generic_Perm;

Task/Permutations/Ada/permutations-2.ada

@@ -1,71 +0,0 @@
-package body Generic_Perm is
-
-
-   procedure Set_To_First(P: out Permutation; Is_Last: out Boolean) is
-   begin
-      for I in P'Range loop
-	 P (I) := I;
-      end loop;
-      Is_Last := P'Length = 1;
-      -- if P has a single element, the fist permutation is the last one
-   end Set_To_First;
-
-   procedure Go_To_Next(P: in out Permutation; Is_Last: out Boolean) is
-
-      procedure Swap (A, B : in out Integer) is
-         C : Integer := A;
-      begin
-         A := B;
-         B := C;
-      end Swap;
-
-      I, J, K : Element;
-   begin
-      -- find longest tail decreasing sequence
-      -- after the loop, this sequence is I+1 .. n,
-      -- and the ith element will be exchanged later
-      -- with some element of the tail
-      Is_Last := True;
-      I := N - 1;
-      loop
-	 if P (I) < P (I+1)
-	 then
-	    Is_Last := False;
-	    exit;
-	 end if;
-	
-	 -- next instruction will raise an exception if I = 1, so
-	 -- exit now (this is the last permutation)
-	 exit when I = 1;
-	 I := I - 1;
-      end loop;
-
-      -- if all the elements of the permutation are in
-      -- decreasing order, this is the last one
-      if Is_Last then
-	 return;
-      end if;
-
-      -- sort the tail, i.e. reverse it, since it is in decreasing order
-      J := I + 1;
-      K := N;
-      while J < K loop
-	 Swap (P (J), P (K));
-	 J := J + 1;
-	 K := K - 1;
-      end loop;
-
-      -- find lowest element in the tail greater than the ith element
-      J := N;
-      while P (J) > P (I) loop
-	 J := J - 1;
-      end loop;
-      J := J + 1;
-
-      -- exchange them
-      -- this will give the next permutation in lexicographic order,
-      -- since every element from ith to the last is minimum
-      Swap (P (I), P (J));
-   end Go_To_Next;
-
-end Generic_Perm;

Task/Permutations/Ada/permutations-3.ada

@@ -1,30 +0,0 @@
-with Ada.Text_IO, Ada.Command_Line, Generic_Perm;
-
-procedure Print_Perms is
-   package CML renames Ada.Command_Line;
-   package TIO renames Ada.Text_IO;
-begin
-   declare
-      package Perms is new Generic_Perm(Positive'Value(CML.Argument(1)));
-      P : Perms.Permutation;
-      Done : Boolean := False;
-
-      procedure Print(P: Perms.Permutation) is
-      begin
-         for I in P'Range loop
-            TIO.Put (Perms.Element'Image (P (I)));
-         end loop;
-         TIO.New_Line;
-      end Print;
-   begin
-      Perms.Set_To_First(P, Done);
-      loop
-         Print(P);
-         exit when Done;
-         Perms.Go_To_Next(P, Done);
-      end loop;
-   end;
-exception
-   when Constraint_Error
-     => TIO.Put_Line ("*** Error: enter one numerical argument n with n >= 1");
-end Print_Perms;