لعبة الثعبان في C++: نسخة طرفية تعمل بالأدوار باستخدام WASD

#include <algorithm>
#include <iostream>
#include <random>
#include <stdexcept>
#include <utility>
#include <vector>

class SnakeGame {
public:
    using Cell = std::pair<int, int>;
private:
    int width, height;
    std::vector<Cell> body{{3, 3}, {2, 3}, {1, 3}};
    Cell direction{1, 0};
    Cell food{-1, -1};
    bool alive = true, won = false;
    std::mt19937 rng;
    void spawnFood() {
        std::vector<Cell> freeCells;
        for (int y = 0; y < height; ++y)
            for (int x = 0; x < width; ++x)
                if (std::find(body.begin(), body.end(), Cell{x, y}) == body.end())
                    freeCells.emplace_back(x, y);
        if (freeCells.empty()) { won = true; food = {-1, -1}; return; }
        std::uniform_int_distribution<std::size_t> pick(0, freeCells.size() - 1);
        food = freeCells[pick(rng)];
    }
public:
    explicit SnakeGame(int w = 12, int h = 8, unsigned seed = std::random_device{}())
        : width(w), height(h), rng(seed) {
        if (w < 4 || h < 4 || w > 40 || h > 20)
            throw std::invalid_argument("Use width 4..40 and height 4..20.");
        spawnFood();
    }
    bool running() const { return alive && !won; }
    bool hasWon() const { return won; }
    std::size_t score() const { return body.size() - 3; }
    const std::vector<Cell>& cells() const { return body; }
    Cell foodCell() const { return food; }
    bool step(char command) {
        if (!running()) return false;
        Cell nextDirection = direction;
        switch (command) {
            case 'w': nextDirection = {0, -1}; break;
            case 's': nextDirection = {0, 1}; break;
            case 'a': nextDirection = {-1, 0}; break;
            case 'd': nextDirection = {1, 0}; break;
            default: return false;
        }
        if (nextDirection.first == -direction.first && nextDirection.second == -direction.second)
            nextDirection = direction; // Ignore an immediate reverse.
        direction = nextDirection;
        Cell next{body.front().first + direction.first, body.front().second + direction.second};
        if (next.first < 0 || next.first >= width || next.second < 0 || next.second >= height) {
            alive = false; return true;
        }
        bool grows = next == food;
        auto stop = grows ? body.end() : body.end() - 1; // Tail moves away unless growing.
        if (std::find(body.begin(), stop, next) != stop) { alive = false; return true; }
        body.insert(body.begin(), next);
        if (grows) spawnFood();
        else body.pop_back();
        return true;
    }
    void draw(std::ostream& output) const {
        output << "Score: " << score() << '\n';
        for (int y = -1; y <= height; ++y) {
            for (int x = -1; x <= width; ++x) {
                Cell cell{x, y};
                char symbol = ' ';
                if (x == -1 || x == width || y == -1 || y == height) symbol = '#';
                else if (cell == body.front()) symbol = 'O';
                else if (std::find(body.begin(), body.end(), cell) != body.end()) symbol = 'o';
                else if (cell == food) symbol = '*';
                output << symbol;
            }
            output << '\n';
        }
    }
};

int main() {
    SnakeGame game;
    std::cout << "Turn-based Snake: enter w/a/s/d then Enter; q quits.\n";
    while (game.running()) {
        game.draw(std::cout);
        char command{};
        if (!(std::cin >> command) || command == 'q') return 0;
        if (!game.step(command)) std::cout << "Use lowercase w/a/s/d.\n";
    }
    game.draw(std::cout);
    std::cout << (game.hasWon() ? "You filled the board!\n" : "Game over.\n");
}