Text based game “Hunt the Wumpus” Version 3

Question

this is a follow up of:Text based game “Hunt the Wumpus” Version 2

this code was used as a base to turn this game into a gui game with fltk: Hunt the Wumpus GUI (FLTK)

I took the suggestions made there and corrected the code. I think now it got a lot more simple.

Please let me know if you still find something smelly in the code. After this is reviewd i will turn this into a GUI game were the dungeon is displayed.

wumpus.h

#pragma once

#include <array> 
#include <vector>

namespace wumpus {

    using Room_number = int;

    class Dungeon {
    public:
        Dungeon();
        void indicate_hazards();
        bool shoot_arrow(std::vector<int> tar_rooms);
        bool move_wumpus();
        bool move_player(Room_number target_room);
        Room_number select_room_to_move();
        std::array<Room_number, 3> get_neighbour_rooms() const;

        void show_state_of_dungeon();   //only used for debug
    private:
        struct Room {
            std::array <Room*, 3> neighbors{ nullptr }; //pointer to 3 rooms next to this room
            Room_number room_number{ 0 };
            bool has_wumpus{ false };
            bool has_pit{ false };
            bool has_bat{ false };
            bool has_player{ false };
        };

        static constexpr int count_of_pits = 3;
        static constexpr int count_of_bats = 3;

        int arrows = 5;

        std::array<Room, 20> rooms
        { 
            {
                { &rooms[1] ,&rooms[4], &rooms[19] },
                { &rooms[0] ,&rooms[2], &rooms[17] },
                { &rooms[1] ,&rooms[3], &rooms[15] },
                { &rooms[2] ,&rooms[4], &rooms[13] },
                { &rooms[0] ,&rooms[3], &rooms[5] },
                { &rooms[4] ,&rooms[6], &rooms[12] },
                { &rooms[5] ,&rooms[7], &rooms[19] },
                { &rooms[6] ,&rooms[8], &rooms[11] },
                { &rooms[7] ,&rooms[9], &rooms[18] },
                { &rooms[8] ,&rooms[10], &rooms[16] },
                { &rooms[9] ,&rooms[11], &rooms[14] },
                { &rooms[7] ,&rooms[10], &rooms[12] },
                { &rooms[5] ,&rooms[11], &rooms[13] },
                { &rooms[3] ,&rooms[12], &rooms[14] },
                { &rooms[10] ,&rooms[13], &rooms[15] },
                { &rooms[2] ,&rooms[14], &rooms[16] },
                { &rooms[9] ,&rooms[15], &rooms[17] },
                { &rooms[1] ,&rooms[16], &rooms[18] },
                { &rooms[8] ,&rooms[17], &rooms[19] },
                { &rooms[0] ,&rooms[6], &rooms[18] },
            } 

        };
    };

    int get_random(int min, int max);
    void hunt_the_wumpus();
    void instructions();

    std::vector<Room_number> select_rooms_to_shoot();

}

wumpus.cpp

#include <iostream>
#include <random>
#include <string>
#include <sstream>

#include "wumpus.h"

namespace wumpus {

    Dungeon::Dungeon()
    {
        // create room numbers
        std::array<Room_number,20> random_room_numbers;

        for (size_t i = 0; i < rooms.size(); ++i) {
            random_room_numbers[i] = i + 1;
        }

        //generate random numbers to use to put room numbers random
        std::random_device rd;
        std::mt19937 g(rd());
        std::shuffle(random_room_numbers.begin(), random_room_numbers.end(),g);

        // add room numbers randomly
        for (size_t i = 0; i < rooms.size(), i < random_room_numbers.size(); ++i) {
            rooms[i].room_number = random_room_numbers[i];
        }

        std::size_t i{ 0 };
        rooms[i++].has_player = true;
        rooms[i++].has_wumpus = true;

        for (auto pits{ count_of_pits }; pits; --pits) {
            rooms[i++].has_pit = true;
        }

        for (auto bats{ count_of_bats }; bats; --bats) {
            rooms[i++].has_bat = true;
        }

        std::shuffle(rooms.begin(), rooms.end(), g);
    }

    void Dungeon::indicate_hazards()
    {
        bool is_first_bat = true;
        bool is_first_pit = true;

        // find the player
        auto player_room{ std::find_if(rooms.begin(), rooms.end(), [](const Room &r) { return r.has_player; }) };

        for (auto& x : player_room->neighbors) {
            if (x->has_wumpus) { 
                std::cout << "I smell the wumpus\n";
            }
            if (is_first_pit && x->has_pit) {
                is_first_pit = false;
                std::cout << "I feel a breeze\n";
            }
            if (is_first_bat && x->has_bat) {
                is_first_bat = false;
                std::cout << "I hear a bat\n";
            }
        }

        std::cout   << "You are in room " << player_room->room_number << "\n"
                    << "You have "<<arrows<< " arrow(s) left\n"
                    << "Tunnels lead to rooms " 
                    << player_room->neighbors[0]->room_number << ", "
                    << player_room->neighbors[1]->room_number << " and "
                    << player_room->neighbors[2]->room_number << "\n"
                    << "what do you want to do? (M)ove or (S)hoot?\n";
    }

    bool Dungeon::shoot_arrow(std::vector<int> target_rooms)
        //trys to shoot in the supplied tar rooms an arrow
        //if the wumpus is hit returns true to indicate victory
        //moves the wumpus on fail
    {
        --arrows;

        // find the player
        auto player_room{ std::find_if(rooms.begin(), rooms.end(), [](const Room &r) { return r.has_player; }) };

        for (const auto& target : target_rooms){

            bool room_reached = false;

            for (const auto& neigbour : player_room->neighbors) {

                if (neigbour->room_number == target) {
                    room_reached = true;

                    if (rooms[neigbour->room_number - 1].has_wumpus) {
                        std::cout << "!!!!!!YOU WON!!!!!!: You killed the Wumpus in room " << rooms[neigbour->room_number - 1].room_number << "\n";
                        return true;
                    }
                    break;
                }
            }
            if (!room_reached) {    
                std::cout << "Room " << target << " could not be reached from arrow\n";
                return false;
            }           
        }
        if (arrows == 0) {
            std::cout << "You lost: You ran out of arrows";
            return true;
        }
        return false;
    }

    bool Dungeon::move_wumpus() 
    {
        auto direction = get_random(0, 3);
        if (direction == 3) {               // 25% chance that wumpus won't move
            return false;
        }

        // find the wumpus
        auto wumpus_room{ std::find_if(rooms.begin(), rooms.end(), [](const Room &r) { return r.has_wumpus; }) };

        // move him
        wumpus_room->has_wumpus = false;
        auto new_room = wumpus_room->neighbors[direction];
        new_room->has_wumpus = true;

        if (new_room->has_player) {
            std::cout << "You lost: Wumpus enters your room and eats you\n";
            return true;
        }
        return false;
    }

    bool Dungeon::move_player(Room_number target_room_number)
        //trys to move player to the selected room
        //if deadly hazard like pit or wumpus is found return game over = true;
        //if bat is found choose new random room free from hazards to put the player
    {

        // find the player
        auto player_room{ std::find_if(rooms.begin(), rooms.end(), [](const Room &r) { return r.has_player; }) };

        for (auto& x : player_room->neighbors) {

            if (x->room_number == target_room_number) {
                if (x->has_wumpus) {
                    std::cout << "You lost: You got eaten by the Wumpus\n";
                    return true;
                }
                else if (x->has_pit) {
                    std::cout << "You lost: You fell in a bottomless pit\n";
                    return true;
                }
                else if (x->has_bat) {
                    std::cout << "Gigantic bat appeared!!!\n";
                    std::cout << "You got dragged to a new room\n";

                    //Only put player in empty room
                    Room* bat_destionation_room = nullptr;
                    do{
                        bat_destionation_room = &rooms[get_random(0, rooms.size() - 1)];
                    } while (bat_destionation_room->has_wumpus || bat_destionation_room->has_pit || bat_destionation_room->has_bat || bat_destionation_room->has_player);

                    player_room->has_player = false;
                    bat_destionation_room->has_player = true;
                    return false;
                }
                else {
                    player_room->has_player = false;
                    auto target_room = &rooms[target_room_number];
                    target_room->has_player = true;
                    return false;
                }
            }
        }
        std::cerr << "Dungeon::move_player: Unknown target room entered";
        return false;
    }

    Room_number Dungeon::select_room_to_move()
    {
        for (;;) {

            std::cout << "To where??\n";

            Room_number target = 0;
            std::cin >> target;

            if (std::cin.fail()) {
                std::cin.clear();
                std::cin.ignore(999, '\n');
                continue;
            }

            auto neighbor = get_neighbour_rooms();

            if (target == neighbor[0] || target == neighbor[1] || target == neighbor[2])
                return target;
        }
    }

    std::array<Room_number, 3> Dungeon::get_neighbour_rooms() const
    {
        // find the player
        auto player_room{ std::find_if(rooms.begin(), rooms.end(), [](const Room &r) { return r.has_player; }) };

        return std::array<Room_number, 3>{
            player_room->neighbors[0]->room_number,
            player_room->neighbors[1]->room_number,
            player_room->neighbors[2]->room_number
        };
    }

    void Dungeon::show_state_of_dungeon()
    {
        auto print_rooms = rooms;

        std::sort(print_rooms.begin(), print_rooms.end(), [](const Room &a, const Room &b) { return b.room_number > a.room_number; });

        for (const auto&room : print_rooms) {
            std::cout << "Room " << room.room_number << " connects to: ";

            for (const auto&neighbor : room.neighbors) {
                if (neighbor != nullptr) {
                    std::cout << neighbor->room_number << " ";
                }
                else {
                    std::cout << "np" << " ";
                }
            }

            std::cout << " ";
            if (room.has_wumpus) {
                std::cout << "wumpus:" << room.has_wumpus << " ";
            }
            if (room.has_pit) {
                std::cout << "pit:" << room.has_pit << " ";
            }
            if (room.has_bat) {
                std::cout << "bat:" << room.has_bat << " ";
            }
            if (room.has_player) {
                std::cout << "player:" << room.has_player << " ";
            }
            std::cout << "\n";
        }
    }

    //-------------------------------------------------------------
    //Helper functions
    //-------------------------------------------------------------

    int get_random(int min, int max)
    {
        static std::random_device rd;
        static std::mt19937 mt(rd());
        std::uniform_int_distribution<int> distribution(min, max);
        return distribution(mt);
    }

    void hunt_the_wumpus()
    {
        instructions();

        for (;;)        // restart game
        {
            Dungeon dungeon;

            dungeon.show_state_of_dungeon();

            for (;;) {      // current room handle

                dungeon.indicate_hazards();

                std::string in;
                std::cin >> in;
                if (std::cin.fail()) {
                    std::cin.clear();
                    std::cin.ignore(999, '\n');
                    continue;
                }

                bool game_over = false;

                if (in == "m" || in == "M" || in == "Move" || in == "move") {
                    game_over = dungeon.move_player(dungeon.select_room_to_move());
                }
                else if (in == "s" || in == "S" || in == "Shoot" || in == "shoot") {

                    game_over = dungeon.shoot_arrow(select_rooms_to_shoot());

                    if (game_over == true) { 
                        break; 
                    }
                    game_over = dungeon.move_wumpus();
                }
                else if (in == "cheat") {       // secret menue to show dungeon state 
                    dungeon.show_state_of_dungeon();
                }
                if (game_over == true) {
                    break;
                }
            }

            std::cout << "Press any key to start a new game or (q)uit to end game\n";
            std::string in;
            std::cin >> in;

            if (in == "q" || in == "Q" || in == "Quit" || in == "quit")
                break;
        }
    }

    void instructions()
    {
        std::cout <<R"(Welcome to "Hunt the Wumpus"!
The wumpus lives in a cave of rooms.Each room has 3 tunnels leading to
other rooms. (Look at a dodecahedron to see how this works - if you don't know
what a dodecahedron is, ask someone).

Hazards
Bottomless pits - two rooms have bottomless pits in them. If you go there, you
fall into the pit(and lose!)
Super bats - two other rooms have super bats.If you go there, a bat grabs you
and takes you to some other room at random. (Which may be troublesome).

Wumpus
The wumpus is not bothered by hazards(he has sucker feet and is too big for a
bat to lift).Usually he is asleep.Two things wake him up : you shooting an
arrow or you entering his room."

If the wumpus wakes he moves(p = .75) one room or stays still(p = .25).After
that, if he is where you are, he eats you up and you lose!"

Each turn you may move or shoot a crooked arrow.
Moving: you can move one room(thru one tunnel).
Arrows : you have 5 arrows.You lose when you run out.Each arrow can go from 1
to 3 rooms.You aim by telling the computer the rooms you want the arrow to go
to.If the arrow can't go that way (if no tunnel) it moves at random to the
next room.If the arrow hits the wumpus, you win.If the arrow hits you, you lose.

Warnings
When you are one room away from a wumpus or hazard, the computer says :

Wumpus: "I smell the wumpus"
Bat : "I hear a bat"
Pit : "I feel a breeze"


"Press any key to start")";

        char c;
        std::cin.get(c);
    }

    std::vector<Room_number> select_rooms_to_shoot()
    {
        for(;;){
            std::cout << "Enter the rooms you want to shoot the arrow (e.g. 2-3-12, e.g. 4-5, e.g. 2)\n";

            std::string input;
            std::cin >> input;

            std::istringstream ist{ input };

            std::vector<int> target_rooms;

            bool bad_input = false;

            while (!ist.eof()) {

                int room_number;
                ist >> room_number;

                if (ist.fail()) {
                    bad_input = true;
                    break;
                }

                target_rooms.push_back(room_number);

                if (target_rooms.size() == 3 || ist.eof())
                    break;

                char seperator;
                ist >> seperator;

                if (ist.fail()) {
                    bad_input = true;
                    break;
                }
                if ((seperator != '-')   || (target_rooms.size() > 3)) {
                    bad_input = true; 
                    break; 
                }
            }

            if (bad_input) {
                continue;
            }
            else {
                return target_rooms;
            }
        }
    }
}

main.cpp

#include <iostream>
#include "wumpus.h"


int main()
try {
    wumpus::hunt_the_wumpus();
}
catch (std::runtime_error& e) {
    std::cerr << e.what() << "\n";
    std::cin.get();
}
catch (...) {
    std::cerr << "unknown error\n";
    std::cin.get();
}

Answer 1

I highly recommend you compile your code with clang and use all of its facilities (like sanitizer, which didn't find anything, so good job). Compiling your code with -Wall -Wextra -pedantic -pedantic-errors results in 81 warnings!!

To be fair, some of those warnings are stylistic (-Wmissing-braces), but some of them are correct (-Wunitialized) and there is even a bug in your code uncovered by a warning:

for (size_t i = 0; i < rooms.size(), i < random_room_numbers.size(); ++i)
//                 ^^^^^^^^^^^^^^^^
//               discarded expression

It's not actually a bug, because rooms and random_room_numbers have the same size. More on that later.

As a side note, it's very interesting that you're using try-catch function bodies; I've never seen one of those "in the wild".

1. Don't catch exceptions by reference, catch them by const& or your handler will not get called if I throw v; where v is an lvalue.

2. I'd recommend to use single character literals instead of string literals if you're only going to put in one character (see main.cpp:10); that's a stylistic issue however (feel free to ignore those).

3. You should be consistent. Some things are not (space before < with templates for example). An automated tool (like clang-format) helps a lot for me.

4. Typos: seperator => separator; menue => menu;

5. You don't actually need to catch any exceptions, because not of part of your code throws an exception.

6. (opinion) You should mark class that aren't supposed to be inherited from as final.

7. The -Wuninitialized warning is pretty useful: &rooms[1] dereferences uninitialized memory. rooms[1] returns the first element of rooms, but at that point rooms hasn't been initialized yet. You'll need to defer initialization.

8. The initialization of random_room_numbers can be simplified using std::iota:

   std::iota(random_room_numbers.begin(), random_room_numbers.end(), 1);
   

9. To guarantee that random_room_numbers and rooms always have the same size, use a constant:

   static constexpr int total_rooms = 20;
   

10. (opinion) I'd suggest to name the member variable room_number just number, because the class is already a room, so it's implied.

11. Use asserts to guard against (accidental) precondition violations. For example, in Dungeon::indicate_hazards, you are assuming that player_room != rooms.end(). I'd put an assert(player_room != rooms.end() && "..."); afterwards just to be sure. (In C++20 you'd use contracts for this).

12. Because you're not going to modify target_rooms (in Dungeon::shoot_arrow), take it by const&.

13. Sometimes you use Room_number (+1) for a room number, but you also use just an int :(. Consistency!

14. std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n'); is safer than some random 999. It also fixes a bug that you had: Try to enter a whitespace followed by a newline. This results in 999 characters been ignored and the game isn't playable anymore.

    There is an exception for the maximum amount, which is why it works in that case, and not in the 999 case.

15. Instead of checking for stream failure (in Dungeon::select_room_to_move) using fail, usestd::cin'soperator bool:if (!std::cin) /fail/;`.

16. if (game_over == true) can be simplified to if (game_over).

17. The introduction text is not up-to-date. There are three pits and super bats, not two. Might want to use the actual variables instead of hardcoding text.

18. It's my understanding that neighbors cannot ever be nullptr, so the extra if statement for it is unnecessary (wumpus.cpp:226). Might want to consider using an assert instead.

19. It seems like you are using player_room a lot. You might want to consider using a member variable for that so that you avoid to iterate over (potentially) the whole room container.

20. Dungeon::shoot_arrow has a bug. If I shoot my last arrow into a non-existent room, then I can illegally continue ;)

21. Dungeon::move_player has a bug, it moves the player into the wrong room. That's because rooms is not sorted, so rooms[target_room_number] doesn't get you the room with room_number == target_room_number. Use std::find again :)

Apart from that, I really like your game so good job! :)