Data commit

Task/Nim-game/Ada/nim-game.ada

@@ -0,0 +1,45 @@
+with Ada.Text_IO;
+
+procedure Nim is
+   subtype Token_Range is Positive range 1 .. 3;
+
+   package TIO renames Ada.Text_IO;
+   package Token_IO is new TIO.Integer_IO(Token_Range);
+
+   procedure Get_Tokens(remaining : in Natural; how_many : out Token_Range) is
+   begin
+      loop
+         TIO.Put("How many tokens would you like to take? ");
+         begin
+            Token_IO.Get(TIO.Standard_Input, how_many);
+            exit when how_many < remaining;
+            raise Constraint_Error;
+         exception
+            when TIO.Data_Error | Constraint_Error =>
+               if not TIO.End_Of_Line(TIO.Standard_Input) then
+                  TIO.Skip_Line(TIO.Standard_Input);
+               end if;
+               TIO.Put_Line("Invalid input.");
+         end;
+      end loop;
+   end;
+
+    tokens : Natural := 12;
+    how_many : Token_Range;
+begin
+   loop
+      TIO.Put_Line(tokens'Img & " tokens remain.");
+      -- no exit condition here: human cannot win.
+      Get_Tokens(tokens, how_many);
+      TIO.Put_Line("Human takes" & how_many'Img & " tokens.");
+      tokens := tokens - how_many;
+      -- computer's turn: take the remaining N tokens to amount to 4.
+      how_many := tokens mod 4;
+      TIO.Put_Line("Computer takes" & how_many'Img & " tokens.");
+      tokens := tokens - how_many;
+      Ada.Text_IO.New_Line;
+      exit when tokens = 0;
+   end loop;
+
+   TIO.Put_Line("Computer won!");
+end Nim;