Task: 21 game





Java: import java.util.Random;
import java.util.Scanner;

public class TwentyOneGame {

    public static void main(String[] args) {
        new TwentyOneGame().run(true, 21, new int[] {1, 2, 3});
    }
    
    public void run(boolean computerPlay, int max, int[] valid) {
        String comma = "";
        for ( int i = 0 ; i < valid.length ; i++ ) {
            comma += valid[i];
            if ( i < valid.length - 2 && valid.length >= 3 ) {
                comma += ", ";
            }
            if ( i == valid.length - 2 ) {
                comma += " or ";
            }
        }
        System.out.printf("The %d game.%nEach player chooses to add %s to a running total.%n" + 
                "The player whose turn it is when the total reaches %d will win the game.%n" + 
                "Winner of the game starts the next game.  Enter q to quit.%n%n", max, comma, max);
        int cGames = 0;
        int hGames = 0;
        boolean anotherGame = true;
        try (Scanner scanner = new Scanner(System.in);) {
            while ( anotherGame ) {
                Random r = new Random();
                int round = 0;
                int total = 0;
                System.out.printf("Start game %d%n", hGames + cGames + 1);
                DONE:
                    while ( true ) {
                        round++;
                        System.out.printf("ROUND %d:%n%n", round);
                        for ( int play = 0 ; play < 2 ; play++ ) {
                            if ( computerPlay ) {
                                int guess = 0;
                                
                                for ( int test : valid ) {
                                    if ( total + test == max ) {
                                        guess = test;
                                        break;
                                    }
                                }
                                
                                if ( guess == 0 ) {
                                    for ( int test : valid ) {
                                        if ( total + test >= max ) {
                                            guess = test;
                                            break;
                                        }
                                    }
                                }
                                if ( guess == 0 ) {
                                    guess = valid[r.nextInt(valid.length)];
                                }
                                total += guess;
                                System.out.printf("The computer chooses %d%n", guess);
                                System.out.printf("Running total is now %d%n%n", total);
                                if ( total >= max ) {
                                    break DONE;
                                }
                            }
                            else {
                                while ( true ) {
                                    System.out.printf("Your choice among %s: ", comma);
                                    String line = scanner.nextLine();
                                    if ( line.matches("^[qQ].*") ) {
                                        System.out.printf("Computer wins %d game%s, human wins %d game%s.  One game incomplete.%nQuitting.%n", cGames, cGames == 1 ? "" : "s", hGames, hGames == 1 ? "" : "s");
                                        return;
                                    }
                                    try {
                                        int input = Integer.parseInt(line);
                                        boolean inputOk = false;
                                        for ( int test : valid ) {
                                            if ( input == test ) {
                                                inputOk = true;
                                                break;
                                            }
                                        }
                                        if ( inputOk ) {
                                            total += input;
                                            System.out.printf("Running total is now %d%n%n", total);
                                            if ( total >= max ) {
                                                break DONE;
                                            }
                                            break;
                                        }
                                        else {
                                            System.out.printf("Invalid input - must be a number among %s.  Try again.%n", comma);
                                        }
                                    }
                                    catch (NumberFormatException e) {
                                        System.out.printf("Invalid input - must be a number among %s.  Try again.%n", comma);
                                    }
                                }
                            }
                            computerPlay = !computerPlay;
                        }
                    }
                String win;
                if ( computerPlay ) {
                    win = "Computer wins!!";
                    cGames++;
                }
                else {
                    win = "You win and probably had help from another computer!!";
                    hGames++;
                }
                System.out.printf("%s%n", win);
                System.out.printf("Computer wins %d game%s, human wins %d game%s%n%n", cGames, cGames == 1 ? "" : "s", hGames, hGames == 1 ? "" : "s");
                while ( true ) {
                    System.out.printf("Another game (y/n)? ");
                    String line = scanner.nextLine();
                    if ( line.matches("^[yY]$") ) {
                        
                        System.out.printf("%n");
                        break;
                    }
                    else if ( line.matches("^[nN]$") ) {
                        anotherGame = false;
                        System.out.printf("Quitting.%n");
                        break;
                    }
                    else {
                        System.out.printf("Invalid input - must be a y or n.  Try again.%n");
                    }
                }
            }
        }
    }

}







Ada: with Ada.Text_IO;
with Ada.Numerics.Discrete_Random;

procedure Game_21 is

   procedure Put (Item : String) is
   begin
      for Char of Item loop
         Ada.Text_IO.Put (Char);
         delay 0.010;
      end loop;
   end Put;

   procedure New_Line is
   begin
      Ada.Text_IO.New_Line;
   end New_Line;

   procedure Put_Line (Item : String) is
   begin
      Put (Item);
      New_Line;
   end Put_LIne;

   type Player_Kind is (Human, Computer);
   type Score_Type  is range 0 .. 21;
   subtype Amount_Range is Score_Type range 1 .. 3;

   package Amount_Generators is
     new Ada.Numerics.Discrete_Random (Amount_Range);

   Gen    : Amount_Generators.Generator;
   Total  : Score_Type := 0;
   Choice : Character;
   Player : Player_Kind;
   Amount : Amount_Range;
begin
   Amount_Generators.Reset (Gen);

   Put_Line ("

   Put ("Who is starting human or computer (h/c) ? ");
   Ada.Text_IO.Get_Immediate (Choice);
   New_Line;

   case Choice is
      when 'c' | 'C' =>  Player := Computer;
      when 'h' | 'H' =>  Player := Human;
      when others => return;
   end case;

   Play_Loop : loop
      New_Line;
      Put ("Runing total is "); Put (Total'Image); New_Line;
      New_Line;

      case Player is

         when Human =>
            Put_Line ("It is your turn !");
            Input_Loop : loop
               Put ("Enter choice 1 .. 3 (0 to end) : ");
               Ada.Text_IO.Get_Immediate (Choice);

               case Choice is
                  when '1' .. '3' =>
                     Amount := Amount_Range'Value ("" & Choice);
                     exit Input_Loop;

                  when '0' =>
                     exit Play_Loop;

                  when others =>
                     Put_Line ("Choice must be in 1 .. 3");
               end case;
            end loop Input_Loop;
            New_Line;

         when Computer =>
            delay 1.500;
            Amount := Amount_Generators.Random (Gen);
            Put ("Computer chooses: "); Put (Amount'Image); New_Line;
            delay 0.800;

      end case;

      New_Line;
      Amount := Score_Type'Min (Amount, Score_Type'Last - Total);
      Put ("  "); Put (Total'Image); Put (" + ");  Put (Amount'Image); Put (" = ");
      Total := Total + Amount;
      Put (Total'Image);
      New_Line;

      if Total = 21 then
         New_Line;
         Put ("... and we have a WINNER !!"); New_Line;
         delay 0.500;
         Put_Line ("   ... and the winner is ...");
         delay 1.000;
         Put_Line ("      " & Player'Image);
         exit;
      end if;

      Player := (case Player is
                 when Computer => Human,
                 when Human    => Computer);
   end loop Play_Loop;
end Game_21;