text: // Copyright 2019 DeepMind Technologies Ltd. All rights reserved.
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //     http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  
  #ifndef OPEN_SPIEL_GAMES_LIARS_DICE_H_
  #define OPEN_SPIEL_GAMES_LIARS_DICE_H_
  
  #include <array>
  #include <memory>
  #include <string>
  #include <vector>
  
  #include "open_spiel/spiel.h"
  
  // A simple game that includes chance and imperfect information
  // https://en.wikipedia.org/wiki/Liar%27s_dice
  //
  // Currently only supports a single round and two players.
  //
  // Parameters:
  //   "players"     int    number of players                      (default = 2)
  //   "numdice"     int    number of dice per player              (default = 1)
  //   "numdiceX"    int    overridden number of dice for player X (default = 1)
  
  namespace open_spiel {
  namespace liars_dice {
  
  class LiarsDiceGame;
  
  class LiarsDiceState : public State {
   public:
    explicit LiarsDiceState(std::shared_ptr<const Game> game, int total_num_dice,
                            int max_dice_per_player,
                            const std::vector<int>& num_dice);
    LiarsDiceState(const LiarsDiceState&) = default;
  
    void Reset(const GameParameters& params);
    Player CurrentPlayer() const override;
    std::string ActionToString(Player player, Action action_id) const override;
    std::string ToString() const override;
    bool IsTerminal() const override;
    std::vector<double> Returns() const override;
    std::string InformationStateString(Player player) const override;
    void InformationStateTensor(Player player,
                                absl::Span<float> values) const override;
    void ObservationTensor(Player player,
                           absl::Span<float> values) const override;
    std::unique_ptr<State> Clone() const override;
    std::vector<std::pair<Action, double>> ChanceOutcomes() const override;
    std::vector<Action> LegalActions() const override;
  
   protected:
    void DoApplyAction(Action action_id) override;
  
   private:
    void ResolveWinner();
  
    // Initialized to invalid values. Use Game::NewInitialState().
    Player cur_player_;  // Player whose turn it is.
    int cur_roller_;     // Player currently rolling dice.
    int winner_;
    int loser_;
    int current_bid_;
    int total_num_dice_;
    int total_moves_;
    int calling_player_;  // Player who calls Liar.
    int bidding_player_;  // Player who cast the last bid.
    int max_dice_per_player_;
  
    // Dice outcomes: first indexed by player, then sorted by outcome.
    std::vector<std::vector<int>> dice_outcomes_;
    std::vector<int> num_dice_;         // How many dice each player has.
    std::vector<int> num_dice_rolled_;  // Number of dice currently rolled.
  
    // Used to encode the information state.
    std::vector<int> bidseq_;
    std::string bidseq_str_;
  };
  
  class LiarsDiceGame : public Game {
   public:
    explicit LiarsDiceGame(const GameParameters& params);
    int NumDistinctActions() const override;
    std::unique_ptr<State> NewInitialState() const override;
    int MaxChanceOutcomes() const override;
    int NumPlayers() const override { return num_players_; }
    double MinUtility() const override { return -1; }
    double MaxUtility() const override { return 1; }
    double UtilitySum() const override { return 0; }
    std::vector<int> InformationStateTensorShape() const override;
    std::vector<int> ObservationTensorShape() const override;
    int MaxGameLength() const override;
  
    // Returns the maximum among how many dice each player has. For example,
    // if player 1 has 3 dice and player 2 has 2 dice, returns 3.
    int max_dice_per_player() const { return max_dice_per_player_; }
  
    // Return the total number of dice in the game.
    int total_num_dice() const { return total_num_dice_; }
  
    // Get the quantity and face of the bid from an integer.
    // The bids starts at 1 and go to total_dice*6+1.
    static std::pair<int, int> GetQuantityFace(int bid, int total_dice);
  
   private:
    // Number of players.
    int num_players_;
  
    // Total dice in the game, determines the legal bids.
    int total_num_dice_;
  
    std::vector<int> num_dice_;  // How many dice each player has.
    int max_dice_per_player_;    // Maximum value in num_dice_ vector.
  };
  
  }  // namespace liars_dice
  }  // namespace open_spiel
  
  #endif  // OPEN_SPIEL_GAMES_LIARS_DICE_H_
  