Chutes & Ladders

// compile with "g++ -std=c++11 game.cpp"
#include <utility>
#include <vector>
#include <string>
#include <random>
#include <map>
#include <iostream>
#include <functional>
#include <cstdlib>

class Player
{
  public:
    Player(const std::string &name) : name(name), location(0), encounteredChutes(0), encounteredLadders(0) {}

    std::string getName() const
    {
        return name;
    }

    int getLocation() const
    {
        return location;
    }

    void setLocation(int newLocation)
    {
        location = newLocation;
    }

    int getEncounteredLadders() const
    {
        return encounteredLadders;
    }

    void incEncounteredLadders()
    {
        encounteredLadders++;
    }

    int getEncounteredChutes() const
    {
        return encounteredChutes;
    }

    void incEncounteredChutes()
    {
        encounteredChutes++;
    }

  private:
    std::string name;
    int location;
    int encounteredLadders;
    int encounteredChutes;
};

class Game
{
  public:
    Game()
    {
        // 不知道要不要随机设置ladders 和 chutes?
        ladders = std::vector<std::pair<int, int>>{
            {1, 3},
            {8, 11},
            {20, 33},
            {33, 44},
            {55, 88},
            {70, 90},
        };
        chutes = std::vector<std::pair<int, int>>{
            {10, 4},
            {30, 21},
            {66, 53},
            {80, 71},
            {89, 67},
        };
    }

    // 原文是“requires a player name and location”， 但是我感觉得接收一个player才行。。不然没法记录ladder/chutes的历史(把历史信息包成tuple作为返回值返回的话有点坑)
    void turn(Player &player)
    {
        std::string playerName = player.getName();
        int curLocation = player.getLocation();

        int spinNum = spin();
        int newLocation = curLocation + spinNum;

        // If a player is on square 95 or higher, then a spin which takes them past 100 must be ignored
        // 直接按原文翻译是这样， 不知道要不要考虑95以上有chute的情况。。。
        if (newLocation > 100)
        {
            std::cout << playerName << " remains at " << curLocation << " after spin as " << spinNum << "\n";
            return;
        }

        std::cout << playerName << " moved:" << curLocation << "==>" << newLocation << " after spin as " << spinNum << "\n";
        newLocation = handleLadders(player, newLocation);
        newLocation = handleChutes(player, newLocation);
        player.setLocation(newLocation);
    }

    bool winner(Player &player)
    {
        int curLocation = player.getLocation();
        if (curLocation < 100)
        {
            return false;
        }

        std::cout << player.getName()
                  << " is the winner! He/She encountered "
                  << player.getEncounteredLadders()
                  << " ladders and "
                  << player.getEncounteredChutes()
                  << " chutes \n";
        return true;
    }

  private:
    int spin()
    {
        auto gen = std::mt19937{std::random_device{}()};
        std::uniform_int_distribution<std::mt19937::result_type> dist{1, 6};
        return dist(gen);
    }

    int handleLadders(Player &player, int curLocation)
    {
        for (auto &ladder : ladders)
        {
            if (ladder.first == curLocation)
            {
                player.incEncounteredLadders();
                std::cout << player.getName() << " climbed up an ladder:" << ladder.first << "==>" << ladder.second << "\n";
                return handleLadders(player, ladder.second);
            }
        }
        return curLocation;
    }

    int handleChutes(Player &player, int curLocation)
    {
        for (auto &chute : chutes)
        {
            if (chute.first == curLocation)
            {
                player.incEncounteredChutes();
                std::cout << player.getName() << " fall through an chute:" << chute.first << "==>" << chute.second << "\n";
                return handleChutes(player, chute.second);
            }
        }
        return curLocation;
    }

  private:
    std::vector<std::pair<int, int>> ladders;
    std::vector<std::pair<int, int>> chutes;
};

int main(int argc, char **argv)
{
    std::cout << "Please enter number of players [2-6]:";
    int numberOfPlayers;
    std::cin >> numberOfPlayers;
    if (numberOfPlayers < 2 || numberOfPlayers > 6)
    {
        std::cerr << "number of players must be within [2-6]! You entered:" << numberOfPlayers << "\n";
        return 1;
    }

    std::vector<Player> players;
    for (int i = 1; i != numberOfPlayers + 1; ++i)
    {
        std::cout << "Please enter name of player " << i << ":";
        std::string playerName;
        std::cin >> playerName;
        players.emplace_back(playerName);
    }

    auto gen = std::mt19937{std::random_device{}()};
    std::uniform_int_distribution<std::mt19937::result_type> dist{0, std::mt19937::result_type(players.size()) - 1};
    int nextPlayerIndex = dist(gen);

    Game game = Game{};
    bool gameEnded = false;

    while (!gameEnded)
    {
        auto &player = players[nextPlayerIndex];
        nextPlayerIndex = (nextPlayerIndex + 1) % players.size();

        game.turn(player);
        if ((gameEnded = game.winner(player)))
        {
            break;
        }
    }
}