new files

Task/Bulls-and-cows/Ada/bulls-and-cows.ada

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+with Ada.Text_IO;  use Ada.Text_IO;
+with Ada.Numerics.Discrete_Random;
+
+procedure Bulls_And_Cows is
+   package Random_Natural is new Ada.Numerics.Discrete_Random (Natural);
+   Number : String (1..4);
+begin
+   declare -- Generation of number
+      use Random_Natural;
+      Digit    : String   := "123456789";
+      Size     : Positive := 9;
+      Dice     : Generator;
+      Position : Natural;
+   begin
+      Reset (Dice);
+      for I in Number'Range loop
+         Position := Random (Dice) mod Size + 1;
+         Number (I) := Digit (Position);
+         Digit (Position..Size - 1) := Digit (Position + 1..Size);
+         Size := Size - 1;
+      end loop;
+   end;
+   loop -- Guessing loop
+      Put ("Enter four digits:");
+      declare
+         Guess : String  := Get_Line;
+         Bulls : Natural := 0;
+         Cows  : Natural := 0;
+      begin
+         if Guess'Length /= 4 then
+            raise Data_Error;
+         end if;
+         for I in Guess'Range loop
+            for J in Number'Range loop
+               if Guess (I) not in '1'..'9' or else (I < J and then Guess (I) = Guess (J)) then
+                  raise Data_Error;
+               end if;
+               if Number (I) = Guess (J) then
+                  if I = J then
+                     Bulls := Bulls + 1;
+                  else
+                     Cows := Cows + 1;
+                  end if;
+               end if;
+            end loop;
+         end loop;
+         exit when Bulls = 4;
+         Put_Line (Integer'Image (Bulls) & " bulls," & Integer'Image (Cows) & " cows");
+      exception
+         when Data_Error => Put_Line ("You should enter four different digits 1..9");
+      end;
+   end loop;
+end Bulls_And_Cows;