Data update

Task/Dutch-national-flag-problem/Ada/dutch-national-flag-problem.ada

@@ -1,99 +0,0 @@
-with Ada.Text_IO, Ada.Numerics.Discrete_Random, Ada.Command_Line;
-
-procedure Dutch_National_Flag is
-
-   type Colour_Type is (Red, White, Blue);
-
-   Number: Positive range 2 .. Positive'Last :=
-     Positive'Value(Ada.Command_Line.Argument(1));
-   -- no sorting if the Number of balls is less than 2
-
-   type Balls is array(1 .. Number) of Colour_Type;
-
-   function Is_Sorted(B: Balls) return Boolean is
-      -- checks if balls are in order
-   begin
-      for I in Balls'First .. Balls'Last-1 loop
-         if B(I) > B(I+1) then
-            return False;
-         end if;
-      end loop;
-      return True;
-   end Is_Sorted;
-
-   function Random_Balls return Balls is
-      -- generates an array of random balls, ensuring they are not in order
-      package Random_Colour is new Ada.Numerics.Discrete_Random(Colour_Type);
-      Gen: Random_Colour.Generator;
-      B: Balls;
-   begin
-      Random_Colour.Reset(Gen);
-      loop
-         for I in Balls'Range loop
-            B(I) := Random_Colour.Random(Gen);
-         end loop;
-         exit when (not Is_Sorted(B));
-         -- ... ensuring they are not in order
-      end loop;
-      return B;
-   end Random_Balls;
-
-   procedure Print(Message: String; B: Balls) is
-   begin
-      Ada.Text_IO.Put(Message);
-      for I in B'Range loop
-         Ada.Text_IO.Put(Colour_Type'Image(B(I)));
-         if I < B'Last then
-            Ada.Text_IO.Put(", ");
-         else
-            Ada.Text_IO.New_Line;
-         end if;
-      end loop;
-   end Print;
-
-   procedure Sort(Bls: in out Balls) is
-      -- sort Bls in O(1) time
-
-      Cnt: array(Colour_Type) of Natural := (Red => 0, White => 0, Blue => 0);
-      Col: Colour_Type;
-
-      procedure Move_Colour_To_Top(Bls: in out Balls;
-                                   Colour: Colour_Type;
-                                   Start: Positive;
-                                   Count: Natural) is
-         This: Positive := Start;
-         Tmp: Colour_Type;
-      begin
-         for N in Start .. Start+Count-1 loop
-            while Bls(This) /= Colour loop
-               This := This + 1;
-            end loop; -- This is the first index >= N with B(This) = Colour
-            Tmp := Bls(N); Bls(N) := Bls(This); Bls(This) := Tmp; -- swap
-            This := This + 1;
-         end loop;
-      end  Move_Colour_To_Top;
-
-   begin
-      for Ball in Balls'Range loop
-         -- count how often each colour is found
-         Col := Bls(Ball);
-         Cnt(Col) := Cnt(Col) + 1;
-      end loop;
-      Move_Colour_To_Top(Bls, Red,   Start => 1,          Count => Cnt(Red));
-      Move_Colour_To_Top(Bls, White, Start => 1+Cnt(Red), Count => Cnt(White));
-      -- all the remaining balls are blue
-   end Sort;
-
-   A: Balls := Random_Balls;
-
-begin
-   Print("Original Order: ", A);
-
-   pragma Assert(not Is_Sorted(A));   -- Check if A is unsorted
-
-   Sort(A); -- A = ((Red**Cnt(Red)= & (White**Cnt(White)) & (Blue**Cnt(Blue)))
-
-   pragma Assert(Is_Sorted(A));   -- Check if A is actually sorted
-
-   Print("After Sorting:  ", A);
-end Dutch_National_Flag;